Based on Hall et al. electrotopological state indices（EK） of atom types, two quantitative structure-activity relationship（QSAR） models were developed to estimate and predict the action strength（W） of D（OM）（di...Based on Hall et al. electrotopological state indices（EK） of atom types, two quantitative structure-activity relationship（QSAR） models were developed to estimate and predict the action strength（W） of D（OM）（dimethoxy-methyl-amphetamine） for 18 phenyl-isopropyl-amine dopes（PPAD） through linear method（multiple linear regression, MLR） and non-linear method（Back propagation artificial neural network, BP-ANN）. On the basis of EK, the optimal three-parameter（E14, E9, E7） QSAR model of W for 18 PPAD was constructed. The traditional correlation coefficient（R^2） and cross-validation correlation coefficient（Rcv^2） are 0.878 and 0.815, respectively. The result demonstrates that the model is highly reliable（from the point of view of statistics） and has good predictive ability by using R^2, Rcv^2, VIF, FIT, AIC and F tests. Form the three parameters of the model, it is known that the dominant influence factors of inhibited activity are the molecular structure fragments： =CH–（secondary carbon）, =C〈（tertiary carbon atom） in aromatic ring and –O–（phenol ether bond）. The results showed that the structure parameters E14, E9 and E7 have good rationality and efficiency for the W of phenyl-isopropyl-amine dope（PPAD） analogues. A BP-ANN with 3-3-1 architecture was generated by using three electrotopological state index descriptors（E14, E9, E7） appearing in the MLR model, the above descriptors were inputs and its output was action strength（W）. The nonlinear BP-ANN model has better predictive ability compared to the linear MLR model with R^2 and Rcv^2 of leave-one-out（LOO） to be 0.995 and 0.994, respectively. The regression method gave support to the neural network with physical explanation, which offers a more accurate model for QSAR. Those models can be used in the rational design of higher stimulating extent PPAD, which provide meaningful reference information to improve the detection methods of PPAD.展开更多
Photocatalysis is an important technology for using solar energy to produce hydrogen,convert CO_(2) to synthetic fuels,and decrease persistent pollutant.However,conventional photocatalysts have limitations,including p...Photocatalysis is an important technology for using solar energy to produce hydrogen,convert CO_(2) to synthetic fuels,and decrease persistent pollutant.However,conventional photocatalysts have limitations,including poor spectral absorption,inefficient charge separation,and structural instability under operational stress,which demand innovative durable materials with tailored electronic properties.Nanodiamond(ND)has recently been recognized as a suitable material because of its exceptional chemical stability,superior charge carrier mobility,and possible surface functionalization.While its intrinsic wide bandgap limits its response to visible-light,different methods have been demonstrated to activate its catalytic potential.Here,several emerging strategies for improving the catalytic performance of ND-based photocatalytic systems are summarized,including surface functionalization,plasmonic hybridization,heteroatom doping,and heterostructure design.And the structure-activity relationship and design principle are proposed to improve the light harvesting,charge transport,and redox kinetics for constructing high efficiency ND-based photocatalysts used in the renewable energy and environmental industries.展开更多
Silica aerogel has broad applications in the field of high-temperature thermal insulation due to its low density,low thermal conductivity and high stability.However,its thermal insulation performance deteriorates sign...Silica aerogel has broad applications in the field of high-temperature thermal insulation due to its low density,low thermal conductivity and high stability.However,its thermal insulation performance deteriorates significantly at elevated temperatures exceeding 600℃,primarily due to the collapse of pore structure.Meanwhile,the shielding capacity of SiO_(2) aerogel to the infrared radiation at high temperature is rather low due to the intrinsic properties of SiO_(2).Herein,a strategy for improving the high-temperature stability and infrared shielding properties of SiO_(2) aerogel via Ca doping was explored.Calcium-doped silica aerogel(CSA)powders were prepared by Sol-Gel,hydrothermal,and ambient pressure drying(APD)techniques using water glass and anhydrous calcium chloride as precursors and trimethylchlorosilane as a hydrophobic modifier.The effects of Ca/Si molar ratio in the precursor and hydrothermal conditions(temperature and pH)on the crystalline properties,microscopic morphology and pore structure of CSAs were investigated.The results show that the Ca/Si molar ratio and hydrothermal treatment have significant effects on the microstructure and heat resistance of CSAs in the temperature range of 400-1000℃.The samples sintered at 1000℃have a high specific surface area of 100.1 m^(2)/g and a pore volume of 0.8705 cm^(3)/g,indicating that the CSA has good heat resistance.One-side insulation tests at temperatures up to 600℃show that the sample with a Ca/Si molar ratio of 1.0 has the best insulation performance,with a cold surface temperature of 450℃,which is 27℃lower than that of the pure silica aerogel.展开更多
Herein,antibacterial silver‑doped fluorescent carbon dots(Ag‑CDs)were synthesized through a stepwise hydrothermal method,with polyethyleneimine(PEI),citric acid(CA),and silver nitrate(AgNO3)serving as precursors.The a...Herein,antibacterial silver‑doped fluorescent carbon dots(Ag‑CDs)were synthesized through a stepwise hydrothermal method,with polyethyleneimine(PEI),citric acid(CA),and silver nitrate(AgNO3)serving as precursors.The applicability and antimicrobial efficacy of these nanomaterials were systematically investigated for metal ion sensing.Experimental evidence demonstrated that the Ag‑CDs exhibited a pronounced fluorescence quenching response toward ferric ions(Fe^(3+)),enabling their quantitative determination via a linear concentration‑dependent relationship.These Ag‑CDs exhibited significant inhibitory effects on biofilm growth and disruption for both Escherichia coli and Staphylococcus aureus.Mechanism investigations indicate that Ag‑CDs induced the death of Escherichia coli and Pseudomonas aeruginosa by disrupting their bacterial morphology and structure,triggering the generation of intracellular reactive oxygen species(ROS),and impairing their antioxidant defense system.展开更多
Hard carbon(HC)in sodium-ion batteries is searched by numerous investigations,which can offer the excellent performance of reversible Na^(+)insertion and extraction.The covalent heteroatom doping in HC is recently wor...Hard carbon(HC)in sodium-ion batteries is searched by numerous investigations,which can offer the excellent performance of reversible Na^(+)insertion and extraction.The covalent heteroatom doping in HC is recently worth concentrating,which can dilate the interlayer spacing of graphite to adjust the electrochemical storage performance in carbon anodes.However,the reported doping strategies of the modified HC have only resulted in limited improvement,especially unobvious effects on tuning porous structure.In this study,tannin extract and K_(2)SO_(4) are respectively utilized as carbon source and sulfur source for the fabrication of HC,in which K_(2)SO_(4) can contribute to the heteroatom doping,and the pore forming as well.The tannin-derived sulfur-doped carbon anode shows the excellent cycle stability,achieving a high reversible capacity of 520.5 mAh/g at a current density of 100 mA/g.Even after 500 cycles at a current density of 3 A/g,a high specific capacity of 236.7 mAh/g and a capacity retention rate of 92.6%can be reserved.Compared with the initial carbon,the adsorption energy of Na^(+)is multifold times higher,whereas Na^(+)diffusion energy barriers manyfold decrease.Moreover,the full battery assembled with Na_(3)V_(2)(PO_(4))_(3)/tannin-based HC demonstrates a stable cycling performance.This work can manifest the potentiality of the tannin-based electrode as anode for a high-performance sodium-ion batteries(SIBs),which could especially offer an explanation of Na^(+)storage and solid-electrolyte interface(SEI)stability to the electrochemical performance.展开更多
Developing catalysts with excellent stability while significantly reducing the overpotential of the oxygen evolution reaction(OER) is crucial for advancing overall water splitting(OWS) systems.In this study,we synthes...Developing catalysts with excellent stability while significantly reducing the overpotential of the oxygen evolution reaction(OER) is crucial for advancing overall water splitting(OWS) systems.In this study,we synthesized the electrode material Ce-NiCo-LDHs@SnO_(2)/NF through a two-step hydrothermal reaction,where Ce-doped NiCo-LDHs are grown on nickel foam modified by a SnO_(2) layer.Ce doping adjusts the internal electronic distribution of Ni Co-LDHs,while the introduction of the SnO_(2) layer enhances electron transfer capability.Together,these factors contribute to the reduction of the OER energy barrier and experimental evidence confirms that the reaction proceeds via the lattice oxygen evolution mechanism(LOM).Consequently,Ce-NiCo-LDHs@SnO_(2)/NF exhibits high level electrochemical performance in OER,requiring only 234 m V overpotential to achieve a current density of 10 m A/cm^(2),with a Tafel slope of just 27.39 m V/dec.When paired with Pt/C/NF,an external potential of only 1.54 V is needed to drive OWS to attain a current density amounting to 10 m A/cm^(2).Furthermore,the catalyst demonstrates stability for 100 h during the OWS stability test.This study underscores the feasibility of enhancing the OER performance through Ce doping and the introduction of a conductive SnO_(2) layer.展开更多
Zinc-air batteries(ZABs)are promising candidates for flexible electronics due to their high energy density and low cost.However,their development is hindered by the sluggish kinetics of the oxygen evolution reaction(O...Zinc-air batteries(ZABs)are promising candidates for flexible electronics due to their high energy density and low cost.However,their development is hindered by the sluggish kinetics of the oxygen evolution reaction(OER)and oxygen reduction reaction(ORR).Herein,we present a novel heterostructured electrocatalyst composed of vertically aligned N-doped graphene(NVG)arrays anchored on Ru-doped ceria(RCO)nanofibers,synthesized via a one-step plasma-enhanced chemical vapor deposition process.Notably,during the plasma-enhanced driven NVG growth,Ru nanoparticles are spontaneously in-situ exsolved from the RCO lattice,forming a unique Ru@RCO-NVG heterostructure.Density functional theory calculations reveal that the Ru@RCO-NVG heterojunction induces interfacial electronic redistribution,thereby significantly lowering the energy barriers for both OER and ORR.Benefiting from the synergistic effects,the Ru@RCO-NVG catalyst exhibits exceptional intrinsic activity towards OER/ORR(an overpotential of 370 mV for OER at 10 mA cm^(−2)and a half-wave potential of 0.86 V for ORR),and higher all-solid-state flexible ZAB performance(peak power density of 286.1 mW cm^(−2)),surpassing commercial Pt/C-IrO_(2)catalysts.This work not only advances the integration of synergistic graphene/ceria composites but also offers a promising strategy for designing efficient electrocatalysts for next-generation energy conversion technologies.展开更多
Peroxymonosulfate(PMS)-based advanced oxidation processes(AOPs)are an effective way to remove emerging contaminants(ECs)from water.The catalytic process involving PMS is hindered by the suboptimal electron trans-fer e...Peroxymonosulfate(PMS)-based advanced oxidation processes(AOPs)are an effective way to remove emerging contaminants(ECs)from water.The catalytic process involving PMS is hindered by the suboptimal electron trans-fer efficiency of current catalysts,the further application of AOPs technology is limited.Here,it is proposed that the interfacial electric field can be controlled by bor(B)-doped FeNC catalysts,which shows significant advantages in the efficient generation,release and participation of reactive oxygen species(ROS)in the reaction.The super exchange interaction between Fe sites and N and B sites is realized through the directional transfer of electrons in the interfacial electric field,which ensures the high efficiency and stability of the PMS catalytic process.B doping increases the d orbitals distribution at Fermi level,which facilitates enhanced electron transition activity,thereby promoting the effective generation of (1)^O_(2).At the same time,orbital hybridization causes the center of the d band to move to a lower energy level,which not only contributes to the desorption process of (1)^O_(2),but also accelerates its release.In addition,B-doping also improved the adsorption capacity of organic pollutants and shortened the migration distance of ROS,thereby significantly improving the degradation efficiency of ECs.The B-doping strategy outlined offers a novel approach to the development of FeNC catalysts,it lays a theoretical foundation and offers technical insights for the integration of PMS/AOPs technology in the ECs management.展开更多
β-Ga_(2)O_(3)is a promising candidate for solarblind ultraviolet photodetection owing to its suitable bandgap of approximately 4.9 eV,excellent photoresponse characteristics,and high stability.However,the lack of a s...β-Ga_(2)O_(3)is a promising candidate for solarblind ultraviolet photodetection owing to its suitable bandgap of approximately 4.9 eV,excellent photoresponse characteristics,and high stability.However,the lack of a sufficient driving force within the material leads to extensive bulk charge recombination,limiting its photocurrent and thus posing significant challenges in designing high-performance Ga_(2)O_(3)-based photodetection.In this study,we propose a gradient doping strategy to achieve a Sn-doping concentration gradient along theβ-Ga_(2)O_(3)film thickness.By combining sol-gel synthesis with rapid thermal annealing,a spatially graded band structure with a full-space built-in electric field is constructed,which increases the width of band bending over a large region and is crucial for significantly enhancing carrier separation and transport in the bulk.The resulting gradient Sn-dopedβ-Ga_(2)O_(3)enables exceptional photoelectric performance without an external bias under 254 nm irradiation,including a superior responsivity of 66.88 mA W^(-1),a high detectivity of 8.12×10^(11)Jones,and a fast rise/decay time of 79/65 ms,outstanding most existing similar reported photoelectrochemical(PEC)type optoelectronic devices.Additionally,the device exhibits excellent long-term stability and enables high-resolution underwater ultraviolet imaging.This study demonstrates that the gradient doping strategy provides a feasible approach for enhancing the PEC performance ofβ-Ga_(2)O_(3)photoelectrodes.展开更多
Micro silicon(mSi)is a promising anode candidate for all-solid-state batteries due to its high specific capacity,low side reactions,and high tap density.However,silicon suffers from its poor electronic and ionic condu...Micro silicon(mSi)is a promising anode candidate for all-solid-state batteries due to its high specific capacity,low side reactions,and high tap density.However,silicon suffers from its poor electronic and ionic conductivity,which is particularly severe on a micro scale and in solid-state systems,leading to increased polarization and inferior electrochemical performance.Doping can broaden the transmission pathways and reduce the diffusion energy barrier for electrons and lithium ions.However,achieving effective,uniform doping in mSi is challenging due to its longer diffusion paths and higher energy barriers.Therefore,current doping research is primarily limited to nanosilicon.In this study,we successfully used a Joule-heating activated staged thermal treatment to achieve full-depth doping of germanium(Ge)in the mSi substrate.The Joule-heating process activated the mSi substrate,resulting in abundant vacancy defects that reduced the diffusion barrier of Ge into the silicon lattice and facilitated full-depth Ge doping.Surprisingly,the resulting Si-Ge anode exhibited significantly enhanced electrical conductivity(70 times).Meanwhile,the improved Li-ion conductivity in mSi and the reduced Young’s modulus enhance the electrode reaction kinetics and integrity after cycling.Ge-doped silicon anodes demonstrate excellent electrochemical performance when applied in sulfide solid-state half-cells and full-cells.This work provides substantial insights into the rational structural design of mSi alloyed anode materials,paving the way for the development of high-performance solid-state Li-ion batteries.展开更多
Precise heterometal doping or substitution of specific metal sites in isostructural metal clusters remains a formidable synthetic challenge,despite its transformative potential for modulating excited-state characteris...Precise heterometal doping or substitution of specific metal sites in isostructural metal clusters remains a formidable synthetic challenge,despite its transformative potential for modulating excited-state characteristics and customizing optical properties.In this work,we achieved the precise synthesis of isostructural alloy clusters R/S-Ag_(3)Cu([Ag_(3)Cu(tppm)(R/S-IPTT)]ClO_(4),R/S-IPTT=R/S-4-isopropylthiazolidine-2-thiolate,tppm=tris(diphenylphosphino)methane)in high yield(89%-91%)through selective doping of a Cu(Ⅰ)atom into chiral homometallic cluster enantiomers R/S-Ag_(4)([Ag_(4)(tppm)(R/S-IPTT)]ClO_(4)).In stark contrast to R/S-Ag_(4)(Φ_(em)<0.5%)that displays weak circularly polarized luminescence(CPL)with phosphorescence characteristic,R/S-Ag_(3)Cu(Φ_(em)≈70%)demonstrates strong CPL properties featured with thermally activated delay fluorescence(TADF)at ambient temperature.The selective substitution of the apical Ag(Ⅰ)atom in Ag_(4)triangular pyramid with a Cu(Ⅰ)atom not only gives rise to beyond 100-fold boosting of photoluminescence quantum yield(PLQY),but also leads to more pronounced optically chiral activity of alloy clusters in excited states in view of the larger photoluminescence dissymmetry factors(g_(PL))of R/S-Ag_(3)Cu(-3.5×10^(-3)/3.4×10^(-3))than that of R/S-Ag_(4)(-2.7×10^(-3)/2.6×10^(-3)).Furthermore,compared with chiral homometallic clusters R/S-Cu_(4)([Cu_(4)(tppm)(R/S-IPTT)]ClO_(4))with the same TADF characteristic at ambient temperature,R/S-Ag_(3)Cu manifests 1.7-fold PLQY and 6-fold g_(PL)due to faster reverse intersystem crossing(RISC)and more effective coupling of electric and magnetic transition moments in alloy clusters.This work not only presents a typical example of selective heterometal doping to modulate excited-state properties of isostructural metal clusters,but also gets deeper insight into the doping chemistry of dissimilar metals at the molecular level.展开更多
The development of high-performance solid electrolytes is pivotal for advancing solid-state battery technologies.In this work,we design an oxysulfide-based solid electrolyte Na MgPO_(3)S by combining bond valence theo...The development of high-performance solid electrolytes is pivotal for advancing solid-state battery technologies.In this work,we design an oxysulfide-based solid electrolyte Na MgPO_(3)S by combining bond valence theory and density functional theory calculations.The material features a wide band gap of 4.0 eV and a considerable reduced Na^(+)migration barrier of 0.44 eV,a 1.26-eV decrease compared to pristine Na MgPO_(4)(~1.70 eV).Ab initio molecular dynamics simulations further reveal significantly enhanced ionic conductivity in the oxysulfide-based system compared to the pristine oxide structure.In addition,the calculated decomposition energy indicates that the modified material exhibits good moisture stability.Our findings suggest that sulfur-doping strategy can simultaneously achieve improved ionic conductivity and high moisture stability in oxide solid electrolytes,which could pave the way for designing high-performance solid electrolytes.展开更多
In recent years,the research on superconductivity in one-dimensional(1D)materials has been attracting increasing attention due to its potential applications in low-dimensional nanodevices.However,the critical temperat...In recent years,the research on superconductivity in one-dimensional(1D)materials has been attracting increasing attention due to its potential applications in low-dimensional nanodevices.However,the critical temperature(T_(c))of 1D superconductors is low.In this work,we theoretically investigate the possible high T_(c) superconductivity of(5,5)carbon nanotube(CNT).The pristine(5,5)CNT is a Dirac semimetal and can be modulated into a semiconductor by full hydrogenation.Interestingly,by further hole doping,it can be regulated into a metallic state with the sp^(3)-hybridized σ electrons metalized,and a giant Kohn anomaly appears in the optical phonons.The two factors together enhance the electron–phonon coupling,and lead to high-T_(c) superconductivity.When the hole doping concentration of hydrogenated-(5,5)CNT is 2.5 hole/cell,the calculated T_(c) is 82.3 K,exceeding the boiling point of liquid nitrogen.Therefore,the predicted hole-doped hydrogenated-(5,5)CNT provides a new platform for 1D high-T_(c) superconductivity and may have potential applications in 1D nanodevices.展开更多
Layered oxides have attracted significant attention as cathodes for sodium-ion batteries(SIBs)due to their compositional versatility and tuneable electrochemical performance.However,these materials still face challeng...Layered oxides have attracted significant attention as cathodes for sodium-ion batteries(SIBs)due to their compositional versatility and tuneable electrochemical performance.However,these materials still face challenges such as structural phase transitions,Na^(+)/vacancy ordering,and Jahn–Teller distortion effect,resulting in severe capacity decay and sluggish ion kinetics.We develop a novel Cu/Y dual-doping strategy that leads to the formation of"Na–Y"interlayer aggregates,which act as structural pillars within alkali metal layers,enhancing structural stability and disrupting the ordered arrangement of Na^(+)/vacancies.This disruption leads to a unique coexistence of ordered and disordered Na^(+)/vacancy states with near-zero strain,which significantly improves Na^(+)diffusion kinetics.This structural innovation not only mitigates the unfavorable P2–O2 phase transition but also facilitates rapid ion transport.As a result,the doped material demonstrates exceptional electrochemical performance,including an ultra-long cycle life of 3000 cycles at 10 C and an outstanding high-rate capability of~70 mAh g^(−1)at 50 C.The discovery of this novel interlayer pillar,along with its role in modulating Na^(+)/vacancy arrangements,provides a fresh perspective on engineering layered oxides.It opens up promising new pathways for the structural design of advanced cathode materials toward efficient,stable,and high-rate SIBs.展开更多
Co-free Li-rich Li_(1.2)Ni_(0.2)Mn_(0.6)O_(2)(LR)cathode shows the highest working capacity that can be applied to high-energy density Li-ion batteries(LIBs).However,poor cycle stability and voltage decay caused by ph...Co-free Li-rich Li_(1.2)Ni_(0.2)Mn_(0.6)O_(2)(LR)cathode shows the highest working capacity that can be applied to high-energy density Li-ion batteries(LIBs).However,poor cycle stability and voltage decay caused by phase transition are always hindering its further development.Herein,a novel medium-entropy Li-rich Mn-based cathode material(LRMEF)was synthesized via a simple sol-gel method.The introduction of multivalent ions(Al^(3+)/Cu^(2+)doping at Mn sites and F−doping at O sites)effectively mitigates the Jahn-Teller distortion of Mn ions and suppresses oxygen release.High-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)images confirm that this synergistic doping strategy induces the in-situ formation of an approximately 3 nm-thick spinel surface layer,which significantly enhances structural stability and ion diffusion kinetics.Besides,a series of in-situ/ex-situ characterization methods and density functional theory(DFT)calculations have been carried out to fundamentally shed light on the optimized structure-activity relationship and reaction mechanism.As a result,the LR material with entropy regulation and anion doping exhibits excellent cycling stability(189.2 mAh g^(−1)at 1 C with 84%capacity retention after 300 cycles),rate performance(164.1 mAh g^(−1)at 5 C),and voltage retention(82.7%at 1 C after 300 cycles),demonstrating great application prospects in future high-energy-density LIBs.展开更多
An in-built N^(+)pocket electrically doped tunnel field-effect transistor(ED-TFET)-based biosensor has been reported for the first time.The proposed device begins with a PN junction structure with a control gate(CG)an...An in-built N^(+)pocket electrically doped tunnel field-effect transistor(ED-TFET)-based biosensor has been reported for the first time.The proposed device begins with a PN junction structure with a control gate(CG)and two polarity gates(PG1 and PG2).Utilizing the polarity bias concept,a narrow N^(+)pocket is formed between the source and channel without the need for additional doping steps,achieved through biasing PG1 and PG2 at-1.2 V and 1.2 V,respectively.This method not only addresses issues related to doping control but also eliminates constraints associated with thermal budgets and simplifies the fabrication process compared to traditional TFETs.To facilitate biomolecule sensing within the device,a nanogap cavity is formed in the gate dielectric by selectively etching a section of the polarity gate dielectric layer toward the source side.The investigation into the presence of neutral and charged molecules within the cavities has been conducted by examining variations in the electrical properties of the proposed biosensor.Key characteristics assessed include drain current,energy band,and electric field distribution.The performance of the biosensor is measured using various metrics such as drain current(I_(DS)),subthreshold swing(SS),threshold voltage(V_(TH)),drain current ratio(I_(ON)/I_(OFF)).The proposed in-built N^(+)pocket ED-TFET-based biosensor reaches a peak sensitivity of 1.08×10~(13)for a neutral biomolecule in a completely filled nanogap with a dielectric constant of 12.Additionally,the effects of cavity geometry and different fill factors(FFs)on sensitivity are studied.展开更多
The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batte...The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batteries.However,its poor cycling,owing to highpressure phase transitions,is one of its disadvantages.In this study,Cu/Ti was introduced into NFM111 cathode material using a solidphase method.Through both theoretically and experimentally,this study found that Cu doping provides a higher redox potential in NFM111,improving its reversible capacity and charge compensation process.The introduction of Ti would enhance the cycling stability of the material,smooth its charge and discharge curves,and suppress its high-voltage phase transitions.Accordingly,the NaNi_(0.27)Fe_(0.28)Mn_(0.33)Cu_(0.05)Ti_(0.06)O_(2)sample used in the study exhibited a remarkable rate performance of 142.97 mAh·g^(-1)at 0.1 C(2.0-4.2 V)and an excellent capacity retention of 72.81%after 300 cycles at 1C(1C=150 mA·g^(-1)).展开更多
O3-types layered cathode materials in sodium-ion batteries(SIBs)suffer from the obvious lattice distortion induced by the complex phase transitions during Na^(+)intercalation/deintercalation process,leading to severe ...O3-types layered cathode materials in sodium-ion batteries(SIBs)suffer from the obvious lattice distortion induced by the complex phase transitions during Na^(+)intercalation/deintercalation process,leading to severe structural collapse and performance degradation.Herein,a series of high valence tantalum(Ta^(5+))doped Na(Ni_(0.4)Fe_(0.2)Mn_(0.4))_(1−x)Ta_(x)O_(2)(x=0/0.0025/0.005/0.01)secondary spherical particles are firstly developed,where Ta^(5+)doping enables the refined primary grain with a tightly stacked rod-like morphology.Comprehensive structural analysis via Neutron powder diffraction(NPD)and Synchrotron radiation X-ray diffraction(SXRD)reveals an expanded NaO_(2)slab and a reduction in Na site vacancy.The potential charge compensation mechanism is further illustrated by X-ray absorption spectroscopy(XAS)and X-ray photoelectron spectroscopy(XPS),unveiling a partial reduction from Ni^(3+)to Ni^(2+)with Ta^(5+)doping.In situ X-ray diffraction(in situ XRD)suggests that the decorated sample undergoes a volume change as low as 0.8%,in contrast with the pristine one(1.5%).Thus,the optimized sample with x=0.005 retains an enhanced capacity retention up to 70.4%at 1 C after 300 cycles in half-cell and delivers a high energy density of 251 Wh kg^(-1)(0.1 C)and with a good capacity retention of 81.0%at 1 C after 200 cycles in full-cell.Our findings provide new insights into the mechanism of high valence Ta^(5+)doping in stabilizing layered oxides cathode materials for SIBs.展开更多
Electrochemical CO_(2) reduction reaction(CO_(2)RR) into valuable formate provides a strategy for carbon neutrality.Bismuth(Bi) catalysts,attributed to their appropriate energy barrier of OCHO*intermediate,have demons...Electrochemical CO_(2) reduction reaction(CO_(2)RR) into valuable formate provides a strategy for carbon neutrality.Bismuth(Bi) catalysts,attributed to their appropriate energy barrier of OCHO*intermediate,have demonstrated substantial potential for the advancement of electrocatalytic CO_(2) reduction to formate.However,due to the weak bonding of protons(H^(*)) of Bi,the available protonate of CO_(2) on Bi is insufficient,which limits the formation of OCHO^(*).Prediction by theoretical calculation,chlorine doping can effectively promote the dissociation of H_(2)O and thus achieve effective proton supply.We prepare chlorine-doped Bi(Cl-Bi) via an electrochemical conversion strategy for electroreduction of CO_(2) .An obvious improvement of faradaic efficiency(FE) of formate(96.7% at-0.95 V vs.RHE) can be achieved on Cl-Bi,higher than that of Bi(89.4%).Meanwhile,Cl-Bi has the highest formate production rate of 275 μmol h^(-1)cm^(-2)at-0.95 V vs.RHE,which is 1.2 times higher than that of Bi(224 μmol h^(-1)cm^(-2)).In situ characterizations and kinetic analysis reveal that chlorine doping promotes the activation of H_(2)O and supply sufficient protons to promote the protonation of CO_(2) to OCHO^(*),which is consistent with theoretical calculation.The study presents an effective strategy for rational design of highly efficient electrocatalysts to promote green chemical production.展开更多
This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0...This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.1)Mo_(0.05)O_(3-δ)(B S CNM_(0.05)),Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.05)Mo_(0.1)O_(3-δ)(BSCNM_(0.1)),and Ba_(0.6)Sr_(0.4)Co_(0.85)Mo_(0.15)O_(3-δ)(BSCM)—with Mo doping contents of 5mol%,10mol%,and15mol%,respectively,were successfully prepared using the sol-gel method.The effects of Mo doping on the crystal structure,conductivity,thermal expansion coefficient,oxygen reduction reaction(ORR)activity,and electrochemical performance were systematically evaluated using X-ray diffraction analysis,thermally induced characterization,electrochemical impedance spectroscopy,and single-cell performance tests.The results revealed that Mo doping could improve the conductivity of the materials,suppress their thermal expansion effects,and significantly improve the electrochemical performance.Surface chemical state analysis using X-ray photoelectron spectroscopy revealed that 5mol%Mo doping could facilitate a high adsorbed oxygen concentration leading to enhanced ORR activity in the materials.Density functional theory calculations confirmed that Mo doping promoted the ORR activity in the materials.At an operating temperature of 600℃,the BSCNM_(0.05)cathode material exhibited significantly enhanced electrochemical impedance characteristics,with a reduced area specific resistance of 0.048Ω·cm~2,which was lower than that of the undoped BSCN matrix material by 32.39%.At the same operating temperature,an anode-supported single cell using a BSCNM_(0.05)cathode achieved a peak power density of 1477 mW·cm^(-2),which was 30.71%,56.30%,and 171.50%higher than those of BSCN,BSCNM_(0.1),and B SCM,respectively.The improved ORR activity and electrochemical performance of BSCNM_(0.05)indicate that it can be used as a cathode material in low-temperature solid oxide fuel cells.展开更多
基金supported by the National Natural Science Foundation of China(21075138)special fund of State Key Laboratory of Structural Chemistry(20160003)
文摘Based on Hall et al. electrotopological state indices（EK） of atom types, two quantitative structure-activity relationship（QSAR） models were developed to estimate and predict the action strength（W） of D（OM）（dimethoxy-methyl-amphetamine） for 18 phenyl-isopropyl-amine dopes（PPAD） through linear method（multiple linear regression, MLR） and non-linear method（Back propagation artificial neural network, BP-ANN）. On the basis of EK, the optimal three-parameter（E14, E9, E7） QSAR model of W for 18 PPAD was constructed. The traditional correlation coefficient（R^2） and cross-validation correlation coefficient（Rcv^2） are 0.878 and 0.815, respectively. The result demonstrates that the model is highly reliable（from the point of view of statistics） and has good predictive ability by using R^2, Rcv^2, VIF, FIT, AIC and F tests. Form the three parameters of the model, it is known that the dominant influence factors of inhibited activity are the molecular structure fragments： =CH–（secondary carbon）, =C〈（tertiary carbon atom） in aromatic ring and –O–（phenol ether bond）. The results showed that the structure parameters E14, E9 and E7 have good rationality and efficiency for the W of phenyl-isopropyl-amine dope（PPAD） analogues. A BP-ANN with 3-3-1 architecture was generated by using three electrotopological state index descriptors（E14, E9, E7） appearing in the MLR model, the above descriptors were inputs and its output was action strength（W）. The nonlinear BP-ANN model has better predictive ability compared to the linear MLR model with R^2 and Rcv^2 of leave-one-out（LOO） to be 0.995 and 0.994, respectively. The regression method gave support to the neural network with physical explanation, which offers a more accurate model for QSAR. Those models can be used in the rational design of higher stimulating extent PPAD, which provide meaningful reference information to improve the detection methods of PPAD.
文摘Photocatalysis is an important technology for using solar energy to produce hydrogen,convert CO_(2) to synthetic fuels,and decrease persistent pollutant.However,conventional photocatalysts have limitations,including poor spectral absorption,inefficient charge separation,and structural instability under operational stress,which demand innovative durable materials with tailored electronic properties.Nanodiamond(ND)has recently been recognized as a suitable material because of its exceptional chemical stability,superior charge carrier mobility,and possible surface functionalization.While its intrinsic wide bandgap limits its response to visible-light,different methods have been demonstrated to activate its catalytic potential.Here,several emerging strategies for improving the catalytic performance of ND-based photocatalytic systems are summarized,including surface functionalization,plasmonic hybridization,heteroatom doping,and heterostructure design.And the structure-activity relationship and design principle are proposed to improve the light harvesting,charge transport,and redox kinetics for constructing high efficiency ND-based photocatalysts used in the renewable energy and environmental industries.
文摘Silica aerogel has broad applications in the field of high-temperature thermal insulation due to its low density,low thermal conductivity and high stability.However,its thermal insulation performance deteriorates significantly at elevated temperatures exceeding 600℃,primarily due to the collapse of pore structure.Meanwhile,the shielding capacity of SiO_(2) aerogel to the infrared radiation at high temperature is rather low due to the intrinsic properties of SiO_(2).Herein,a strategy for improving the high-temperature stability and infrared shielding properties of SiO_(2) aerogel via Ca doping was explored.Calcium-doped silica aerogel(CSA)powders were prepared by Sol-Gel,hydrothermal,and ambient pressure drying(APD)techniques using water glass and anhydrous calcium chloride as precursors and trimethylchlorosilane as a hydrophobic modifier.The effects of Ca/Si molar ratio in the precursor and hydrothermal conditions(temperature and pH)on the crystalline properties,microscopic morphology and pore structure of CSAs were investigated.The results show that the Ca/Si molar ratio and hydrothermal treatment have significant effects on the microstructure and heat resistance of CSAs in the temperature range of 400-1000℃.The samples sintered at 1000℃have a high specific surface area of 100.1 m^(2)/g and a pore volume of 0.8705 cm^(3)/g,indicating that the CSA has good heat resistance.One-side insulation tests at temperatures up to 600℃show that the sample with a Ca/Si molar ratio of 1.0 has the best insulation performance,with a cold surface temperature of 450℃,which is 27℃lower than that of the pure silica aerogel.
文摘Herein,antibacterial silver‑doped fluorescent carbon dots(Ag‑CDs)were synthesized through a stepwise hydrothermal method,with polyethyleneimine(PEI),citric acid(CA),and silver nitrate(AgNO3)serving as precursors.The applicability and antimicrobial efficacy of these nanomaterials were systematically investigated for metal ion sensing.Experimental evidence demonstrated that the Ag‑CDs exhibited a pronounced fluorescence quenching response toward ferric ions(Fe^(3+)),enabling their quantitative determination via a linear concentration‑dependent relationship.These Ag‑CDs exhibited significant inhibitory effects on biofilm growth and disruption for both Escherichia coli and Staphylococcus aureus.Mechanism investigations indicate that Ag‑CDs induced the death of Escherichia coli and Pseudomonas aeruginosa by disrupting their bacterial morphology and structure,triggering the generation of intracellular reactive oxygen species(ROS),and impairing their antioxidant defense system.
基金supported by National Natural Science Foundation of China(Nos.32271791,32171709 and 22475053)Hunan Provincial Natural Science Foundation of China(No.2024JJ7643)Natural Science Foundation of Shanghai(No.22ZR1404100).
文摘Hard carbon(HC)in sodium-ion batteries is searched by numerous investigations,which can offer the excellent performance of reversible Na^(+)insertion and extraction.The covalent heteroatom doping in HC is recently worth concentrating,which can dilate the interlayer spacing of graphite to adjust the electrochemical storage performance in carbon anodes.However,the reported doping strategies of the modified HC have only resulted in limited improvement,especially unobvious effects on tuning porous structure.In this study,tannin extract and K_(2)SO_(4) are respectively utilized as carbon source and sulfur source for the fabrication of HC,in which K_(2)SO_(4) can contribute to the heteroatom doping,and the pore forming as well.The tannin-derived sulfur-doped carbon anode shows the excellent cycle stability,achieving a high reversible capacity of 520.5 mAh/g at a current density of 100 mA/g.Even after 500 cycles at a current density of 3 A/g,a high specific capacity of 236.7 mAh/g and a capacity retention rate of 92.6%can be reserved.Compared with the initial carbon,the adsorption energy of Na^(+)is multifold times higher,whereas Na^(+)diffusion energy barriers manyfold decrease.Moreover,the full battery assembled with Na_(3)V_(2)(PO_(4))_(3)/tannin-based HC demonstrates a stable cycling performance.This work can manifest the potentiality of the tannin-based electrode as anode for a high-performance sodium-ion batteries(SIBs),which could especially offer an explanation of Na^(+)storage and solid-electrolyte interface(SEI)stability to the electrochemical performance.
基金supported by the National Natural Science Foundation of China (No.52274304)。
文摘Developing catalysts with excellent stability while significantly reducing the overpotential of the oxygen evolution reaction(OER) is crucial for advancing overall water splitting(OWS) systems.In this study,we synthesized the electrode material Ce-NiCo-LDHs@SnO_(2)/NF through a two-step hydrothermal reaction,where Ce-doped NiCo-LDHs are grown on nickel foam modified by a SnO_(2) layer.Ce doping adjusts the internal electronic distribution of Ni Co-LDHs,while the introduction of the SnO_(2) layer enhances electron transfer capability.Together,these factors contribute to the reduction of the OER energy barrier and experimental evidence confirms that the reaction proceeds via the lattice oxygen evolution mechanism(LOM).Consequently,Ce-NiCo-LDHs@SnO_(2)/NF exhibits high level electrochemical performance in OER,requiring only 234 m V overpotential to achieve a current density of 10 m A/cm^(2),with a Tafel slope of just 27.39 m V/dec.When paired with Pt/C/NF,an external potential of only 1.54 V is needed to drive OWS to attain a current density amounting to 10 m A/cm^(2).Furthermore,the catalyst demonstrates stability for 100 h during the OWS stability test.This study underscores the feasibility of enhancing the OER performance through Ce doping and the introduction of a conductive SnO_(2) layer.
基金supported by the National Natural Science Foundation of China(Grant No.22479133,and No.22469008)the Natural Science Foundation of Guangdong Province(Grant No.2024A1515012235).
文摘Zinc-air batteries(ZABs)are promising candidates for flexible electronics due to their high energy density and low cost.However,their development is hindered by the sluggish kinetics of the oxygen evolution reaction(OER)and oxygen reduction reaction(ORR).Herein,we present a novel heterostructured electrocatalyst composed of vertically aligned N-doped graphene(NVG)arrays anchored on Ru-doped ceria(RCO)nanofibers,synthesized via a one-step plasma-enhanced chemical vapor deposition process.Notably,during the plasma-enhanced driven NVG growth,Ru nanoparticles are spontaneously in-situ exsolved from the RCO lattice,forming a unique Ru@RCO-NVG heterostructure.Density functional theory calculations reveal that the Ru@RCO-NVG heterojunction induces interfacial electronic redistribution,thereby significantly lowering the energy barriers for both OER and ORR.Benefiting from the synergistic effects,the Ru@RCO-NVG catalyst exhibits exceptional intrinsic activity towards OER/ORR(an overpotential of 370 mV for OER at 10 mA cm^(−2)and a half-wave potential of 0.86 V for ORR),and higher all-solid-state flexible ZAB performance(peak power density of 286.1 mW cm^(−2)),surpassing commercial Pt/C-IrO_(2)catalysts.This work not only advances the integration of synergistic graphene/ceria composites but also offers a promising strategy for designing efficient electrocatalysts for next-generation energy conversion technologies.
基金supported by the National Natural Science Foundation of China(No.22278156)the Guangdong Special Support Program Project(No.2021JC060580)+1 种基金the Young Elite Scientists Sponsorship Program by CAST-Doctoral Student Special Plan,the China Scholarship Council Program(No.202406150148)the Natural Science Foundation of Guangdong Province(No.2023A1515011186).
文摘Peroxymonosulfate(PMS)-based advanced oxidation processes(AOPs)are an effective way to remove emerging contaminants(ECs)from water.The catalytic process involving PMS is hindered by the suboptimal electron trans-fer efficiency of current catalysts,the further application of AOPs technology is limited.Here,it is proposed that the interfacial electric field can be controlled by bor(B)-doped FeNC catalysts,which shows significant advantages in the efficient generation,release and participation of reactive oxygen species(ROS)in the reaction.The super exchange interaction between Fe sites and N and B sites is realized through the directional transfer of electrons in the interfacial electric field,which ensures the high efficiency and stability of the PMS catalytic process.B doping increases the d orbitals distribution at Fermi level,which facilitates enhanced electron transition activity,thereby promoting the effective generation of (1)^O_(2).At the same time,orbital hybridization causes the center of the d band to move to a lower energy level,which not only contributes to the desorption process of (1)^O_(2),but also accelerates its release.In addition,B-doping also improved the adsorption capacity of organic pollutants and shortened the migration distance of ROS,thereby significantly improving the degradation efficiency of ECs.The B-doping strategy outlined offers a novel approach to the development of FeNC catalysts,it lays a theoretical foundation and offers technical insights for the integration of PMS/AOPs technology in the ECs management.
基金supported by the National Natural Science Foundation of China(12304102,62574029)Natural Science Foundation of Chongqing(CSTB2023NSCQ-MSX0479)+1 种基金Science and Technology Research Project of Chongqing Education Committee(KJQN202400558)Doctoral Scientific Research Fund of Chongqing Normal University(23XLB029)。
文摘β-Ga_(2)O_(3)is a promising candidate for solarblind ultraviolet photodetection owing to its suitable bandgap of approximately 4.9 eV,excellent photoresponse characteristics,and high stability.However,the lack of a sufficient driving force within the material leads to extensive bulk charge recombination,limiting its photocurrent and thus posing significant challenges in designing high-performance Ga_(2)O_(3)-based photodetection.In this study,we propose a gradient doping strategy to achieve a Sn-doping concentration gradient along theβ-Ga_(2)O_(3)film thickness.By combining sol-gel synthesis with rapid thermal annealing,a spatially graded band structure with a full-space built-in electric field is constructed,which increases the width of band bending over a large region and is crucial for significantly enhancing carrier separation and transport in the bulk.The resulting gradient Sn-dopedβ-Ga_(2)O_(3)enables exceptional photoelectric performance without an external bias under 254 nm irradiation,including a superior responsivity of 66.88 mA W^(-1),a high detectivity of 8.12×10^(11)Jones,and a fast rise/decay time of 79/65 ms,outstanding most existing similar reported photoelectrochemical(PEC)type optoelectronic devices.Additionally,the device exhibits excellent long-term stability and enables high-resolution underwater ultraviolet imaging.This study demonstrates that the gradient doping strategy provides a feasible approach for enhancing the PEC performance ofβ-Ga_(2)O_(3)photoelectrodes.
基金financially supported by the National Key Research and Development Program(2022YFE0127400)the National Natural Science Foundation of China(52172040,52202041,and U23B2077)+1 种基金Taishan Scholar Project of Shandong Province(tsqn202211086,ts202208832,tsqnz20221118)the Fundamental Research Funds for the Central Universities(23CX06055A).
文摘Micro silicon(mSi)is a promising anode candidate for all-solid-state batteries due to its high specific capacity,low side reactions,and high tap density.However,silicon suffers from its poor electronic and ionic conductivity,which is particularly severe on a micro scale and in solid-state systems,leading to increased polarization and inferior electrochemical performance.Doping can broaden the transmission pathways and reduce the diffusion energy barrier for electrons and lithium ions.However,achieving effective,uniform doping in mSi is challenging due to its longer diffusion paths and higher energy barriers.Therefore,current doping research is primarily limited to nanosilicon.In this study,we successfully used a Joule-heating activated staged thermal treatment to achieve full-depth doping of germanium(Ge)in the mSi substrate.The Joule-heating process activated the mSi substrate,resulting in abundant vacancy defects that reduced the diffusion barrier of Ge into the silicon lattice and facilitated full-depth Ge doping.Surprisingly,the resulting Si-Ge anode exhibited significantly enhanced electrical conductivity(70 times).Meanwhile,the improved Li-ion conductivity in mSi and the reduced Young’s modulus enhance the electrode reaction kinetics and integrity after cycling.Ge-doped silicon anodes demonstrate excellent electrochemical performance when applied in sulfide solid-state half-cells and full-cells.This work provides substantial insights into the rational structural design of mSi alloyed anode materials,paving the way for the development of high-performance solid-state Li-ion batteries.
基金supported by the National Natural Science Foundation of China(92061202,21531008,22175181)the Fujian Province Science and Technology Project Program(2022H0041)the Self-deployment Project Research Program of Haixi Institute,Chinese Academy of Sciences(CXZX-2022-GH11)。
文摘Precise heterometal doping or substitution of specific metal sites in isostructural metal clusters remains a formidable synthetic challenge,despite its transformative potential for modulating excited-state characteristics and customizing optical properties.In this work,we achieved the precise synthesis of isostructural alloy clusters R/S-Ag_(3)Cu([Ag_(3)Cu(tppm)(R/S-IPTT)]ClO_(4),R/S-IPTT=R/S-4-isopropylthiazolidine-2-thiolate,tppm=tris(diphenylphosphino)methane)in high yield(89%-91%)through selective doping of a Cu(Ⅰ)atom into chiral homometallic cluster enantiomers R/S-Ag_(4)([Ag_(4)(tppm)(R/S-IPTT)]ClO_(4)).In stark contrast to R/S-Ag_(4)(Φ_(em)<0.5%)that displays weak circularly polarized luminescence(CPL)with phosphorescence characteristic,R/S-Ag_(3)Cu(Φ_(em)≈70%)demonstrates strong CPL properties featured with thermally activated delay fluorescence(TADF)at ambient temperature.The selective substitution of the apical Ag(Ⅰ)atom in Ag_(4)triangular pyramid with a Cu(Ⅰ)atom not only gives rise to beyond 100-fold boosting of photoluminescence quantum yield(PLQY),but also leads to more pronounced optically chiral activity of alloy clusters in excited states in view of the larger photoluminescence dissymmetry factors(g_(PL))of R/S-Ag_(3)Cu(-3.5×10^(-3)/3.4×10^(-3))than that of R/S-Ag_(4)(-2.7×10^(-3)/2.6×10^(-3)).Furthermore,compared with chiral homometallic clusters R/S-Cu_(4)([Cu_(4)(tppm)(R/S-IPTT)]ClO_(4))with the same TADF characteristic at ambient temperature,R/S-Ag_(3)Cu manifests 1.7-fold PLQY and 6-fold g_(PL)due to faster reverse intersystem crossing(RISC)and more effective coupling of electric and magnetic transition moments in alloy clusters.This work not only presents a typical example of selective heterometal doping to modulate excited-state properties of isostructural metal clusters,but also gets deeper insight into the doping chemistry of dissimilar metals at the molecular level.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.22473010,22303114,and 12474372)the Fundamental Research Funds for the Central Universities,Jilin University,the National Key Research and Development Program of China(Grant No.SQ2023YFB2805600)+4 种基金the Natural Science Foundation of Beijing Municipality(Grant No.Z210004)the Fund from the State Key Laboratory of Information Photonics and Optical Communications(Grant No.IPOC2021ZT01)Beijing Nova Program from Beijing Municipal Science and Technology Commission(Grant No.20230484433)Beijing University of Posts and Telecommunications Excellent Ph.D.Students Foundation(Grant No.CX20241078)Beijing Natural Science Foundation(Undergraduate Program)(Grant No.QY24218)。
文摘The development of high-performance solid electrolytes is pivotal for advancing solid-state battery technologies.In this work,we design an oxysulfide-based solid electrolyte Na MgPO_(3)S by combining bond valence theory and density functional theory calculations.The material features a wide band gap of 4.0 eV and a considerable reduced Na^(+)migration barrier of 0.44 eV,a 1.26-eV decrease compared to pristine Na MgPO_(4)(~1.70 eV).Ab initio molecular dynamics simulations further reveal significantly enhanced ionic conductivity in the oxysulfide-based system compared to the pristine oxide structure.In addition,the calculated decomposition energy indicates that the modified material exhibits good moisture stability.Our findings suggest that sulfur-doping strategy can simultaneously achieve improved ionic conductivity and high moisture stability in oxide solid electrolytes,which could pave the way for designing high-performance solid electrolytes.
基金supported by the National Natural Science Foundation of China (Grant Nos.12074213 and 11574108)the Major Basic Program of Natural Science Foundation of Shandong Province (Grant No.ZR2021ZD01)the Natural Science Foundation of Shandong Province (Grant No.ZR2023MA082)。
文摘In recent years,the research on superconductivity in one-dimensional(1D)materials has been attracting increasing attention due to its potential applications in low-dimensional nanodevices.However,the critical temperature(T_(c))of 1D superconductors is low.In this work,we theoretically investigate the possible high T_(c) superconductivity of(5,5)carbon nanotube(CNT).The pristine(5,5)CNT is a Dirac semimetal and can be modulated into a semiconductor by full hydrogenation.Interestingly,by further hole doping,it can be regulated into a metallic state with the sp^(3)-hybridized σ electrons metalized,and a giant Kohn anomaly appears in the optical phonons.The two factors together enhance the electron–phonon coupling,and lead to high-T_(c) superconductivity.When the hole doping concentration of hydrogenated-(5,5)CNT is 2.5 hole/cell,the calculated T_(c) is 82.3 K,exceeding the boiling point of liquid nitrogen.Therefore,the predicted hole-doped hydrogenated-(5,5)CNT provides a new platform for 1D high-T_(c) superconductivity and may have potential applications in 1D nanodevices.
基金supported by the “Pioneer” and “Leading Goose” R&D Program of Zhejiang Province of China (No. 2024C01056)the support from London South Bank University
文摘Layered oxides have attracted significant attention as cathodes for sodium-ion batteries(SIBs)due to their compositional versatility and tuneable electrochemical performance.However,these materials still face challenges such as structural phase transitions,Na^(+)/vacancy ordering,and Jahn–Teller distortion effect,resulting in severe capacity decay and sluggish ion kinetics.We develop a novel Cu/Y dual-doping strategy that leads to the formation of"Na–Y"interlayer aggregates,which act as structural pillars within alkali metal layers,enhancing structural stability and disrupting the ordered arrangement of Na^(+)/vacancies.This disruption leads to a unique coexistence of ordered and disordered Na^(+)/vacancy states with near-zero strain,which significantly improves Na^(+)diffusion kinetics.This structural innovation not only mitigates the unfavorable P2–O2 phase transition but also facilitates rapid ion transport.As a result,the doped material demonstrates exceptional electrochemical performance,including an ultra-long cycle life of 3000 cycles at 10 C and an outstanding high-rate capability of~70 mAh g^(−1)at 50 C.The discovery of this novel interlayer pillar,along with its role in modulating Na^(+)/vacancy arrangements,provides a fresh perspective on engineering layered oxides.It opens up promising new pathways for the structural design of advanced cathode materials toward efficient,stable,and high-rate SIBs.
基金financially supported by the Research and Development Program of China (2022YFA1505700)the National Natural Science Foundation of China (22475214, 22205232, 52102216)+6 种基金the Natural Science Foundation of Fujian Province (2023J06044,2022J01625, 2022-S-002)the Talent Plan of Shanghai BranchChinese Academy of Sciences (CASSHB-QNPD-2023-020)the Selfdeployment Project Research Program of Haixi Institutes,Chinese Academy of Sciences (CXZX-2022-JQ06 and CXZX-2022-GH03)the Anhui Key Laboratory of Nanomaterials and Nanotechnology,the Major Science and Technology Projects in Anhui Province(202305a12020006)the Open Project of State Key Laboratory of Inorganic Synthesis and Preparative Chemistry (2025-22)the Innovation Training Program for College Students(2025019300A, 20250193008)
文摘Co-free Li-rich Li_(1.2)Ni_(0.2)Mn_(0.6)O_(2)(LR)cathode shows the highest working capacity that can be applied to high-energy density Li-ion batteries(LIBs).However,poor cycle stability and voltage decay caused by phase transition are always hindering its further development.Herein,a novel medium-entropy Li-rich Mn-based cathode material(LRMEF)was synthesized via a simple sol-gel method.The introduction of multivalent ions(Al^(3+)/Cu^(2+)doping at Mn sites and F−doping at O sites)effectively mitigates the Jahn-Teller distortion of Mn ions and suppresses oxygen release.High-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)images confirm that this synergistic doping strategy induces the in-situ formation of an approximately 3 nm-thick spinel surface layer,which significantly enhances structural stability and ion diffusion kinetics.Besides,a series of in-situ/ex-situ characterization methods and density functional theory(DFT)calculations have been carried out to fundamentally shed light on the optimized structure-activity relationship and reaction mechanism.As a result,the LR material with entropy regulation and anion doping exhibits excellent cycling stability(189.2 mAh g^(−1)at 1 C with 84%capacity retention after 300 cycles),rate performance(164.1 mAh g^(−1)at 5 C),and voltage retention(82.7%at 1 C after 300 cycles),demonstrating great application prospects in future high-energy-density LIBs.
基金Project supported by the Ministry of Education’s Supply and Demand Matching Employment and Education Project(Grant No.2024110776329)。
文摘An in-built N^(+)pocket electrically doped tunnel field-effect transistor(ED-TFET)-based biosensor has been reported for the first time.The proposed device begins with a PN junction structure with a control gate(CG)and two polarity gates(PG1 and PG2).Utilizing the polarity bias concept,a narrow N^(+)pocket is formed between the source and channel without the need for additional doping steps,achieved through biasing PG1 and PG2 at-1.2 V and 1.2 V,respectively.This method not only addresses issues related to doping control but also eliminates constraints associated with thermal budgets and simplifies the fabrication process compared to traditional TFETs.To facilitate biomolecule sensing within the device,a nanogap cavity is formed in the gate dielectric by selectively etching a section of the polarity gate dielectric layer toward the source side.The investigation into the presence of neutral and charged molecules within the cavities has been conducted by examining variations in the electrical properties of the proposed biosensor.Key characteristics assessed include drain current,energy band,and electric field distribution.The performance of the biosensor is measured using various metrics such as drain current(I_(DS)),subthreshold swing(SS),threshold voltage(V_(TH)),drain current ratio(I_(ON)/I_(OFF)).The proposed in-built N^(+)pocket ED-TFET-based biosensor reaches a peak sensitivity of 1.08×10~(13)for a neutral biomolecule in a completely filled nanogap with a dielectric constant of 12.Additionally,the effects of cavity geometry and different fill factors(FFs)on sensitivity are studied.
基金supported by the Low-Cost Long-Life Batteries program,China(No.WL-24-08-01)the National Natural Science Foundation of China(No.22279007)。
文摘The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batteries.However,its poor cycling,owing to highpressure phase transitions,is one of its disadvantages.In this study,Cu/Ti was introduced into NFM111 cathode material using a solidphase method.Through both theoretically and experimentally,this study found that Cu doping provides a higher redox potential in NFM111,improving its reversible capacity and charge compensation process.The introduction of Ti would enhance the cycling stability of the material,smooth its charge and discharge curves,and suppress its high-voltage phase transitions.Accordingly,the NaNi_(0.27)Fe_(0.28)Mn_(0.33)Cu_(0.05)Ti_(0.06)O_(2)sample used in the study exhibited a remarkable rate performance of 142.97 mAh·g^(-1)at 0.1 C(2.0-4.2 V)and an excellent capacity retention of 72.81%after 300 cycles at 1C(1C=150 mA·g^(-1)).
基金supported by the National Natural Science Foundation of China (52402298, 52172224, 52202228, 22479112)the Science and Technology Correspondent Project of Tianjin(24YDTPJC00240)+3 种基金Science Research Project of Hebei Education Department (BJK2022011)Central Funds Guiding the Local Science and Technology Development of Hebei Province (236Z4404G)the Beijing Tianjin Hebei Basic Research Cooperation Special Project(E2024202273)Tianjin Sci.&Tech. Program (22YFYSHZ00220)
文摘O3-types layered cathode materials in sodium-ion batteries(SIBs)suffer from the obvious lattice distortion induced by the complex phase transitions during Na^(+)intercalation/deintercalation process,leading to severe structural collapse and performance degradation.Herein,a series of high valence tantalum(Ta^(5+))doped Na(Ni_(0.4)Fe_(0.2)Mn_(0.4))_(1−x)Ta_(x)O_(2)(x=0/0.0025/0.005/0.01)secondary spherical particles are firstly developed,where Ta^(5+)doping enables the refined primary grain with a tightly stacked rod-like morphology.Comprehensive structural analysis via Neutron powder diffraction(NPD)and Synchrotron radiation X-ray diffraction(SXRD)reveals an expanded NaO_(2)slab and a reduction in Na site vacancy.The potential charge compensation mechanism is further illustrated by X-ray absorption spectroscopy(XAS)and X-ray photoelectron spectroscopy(XPS),unveiling a partial reduction from Ni^(3+)to Ni^(2+)with Ta^(5+)doping.In situ X-ray diffraction(in situ XRD)suggests that the decorated sample undergoes a volume change as low as 0.8%,in contrast with the pristine one(1.5%).Thus,the optimized sample with x=0.005 retains an enhanced capacity retention up to 70.4%at 1 C after 300 cycles in half-cell and delivers a high energy density of 251 Wh kg^(-1)(0.1 C)and with a good capacity retention of 81.0%at 1 C after 200 cycles in full-cell.Our findings provide new insights into the mechanism of high valence Ta^(5+)doping in stabilizing layered oxides cathode materials for SIBs.
基金financially supported by the Natural Science Foundation of Shandong Province (No.ZR2022QE076)the National Natural Science Foundation of China (No.52202092)the Science and Technology Support Plan for Youth Innovation of Colleges and Universities of Shandong Province of China (No.2023KJ104)。
文摘Electrochemical CO_(2) reduction reaction(CO_(2)RR) into valuable formate provides a strategy for carbon neutrality.Bismuth(Bi) catalysts,attributed to their appropriate energy barrier of OCHO*intermediate,have demonstrated substantial potential for the advancement of electrocatalytic CO_(2) reduction to formate.However,due to the weak bonding of protons(H^(*)) of Bi,the available protonate of CO_(2) on Bi is insufficient,which limits the formation of OCHO^(*).Prediction by theoretical calculation,chlorine doping can effectively promote the dissociation of H_(2)O and thus achieve effective proton supply.We prepare chlorine-doped Bi(Cl-Bi) via an electrochemical conversion strategy for electroreduction of CO_(2) .An obvious improvement of faradaic efficiency(FE) of formate(96.7% at-0.95 V vs.RHE) can be achieved on Cl-Bi,higher than that of Bi(89.4%).Meanwhile,Cl-Bi has the highest formate production rate of 275 μmol h^(-1)cm^(-2)at-0.95 V vs.RHE,which is 1.2 times higher than that of Bi(224 μmol h^(-1)cm^(-2)).In situ characterizations and kinetic analysis reveal that chlorine doping promotes the activation of H_(2)O and supply sufficient protons to promote the protonation of CO_(2) to OCHO^(*),which is consistent with theoretical calculation.The study presents an effective strategy for rational design of highly efficient electrocatalysts to promote green chemical production.
基金financially supported by the National Natural Science Foundation of China(No.22309067)the Open Project Program of the State Key Laboratory of Materials-Oriented Chemical Engineering,China(No.KL21-05)the Marine Equipment and Technology Institute,Jiangsu University of Science and Technology,China(No.XTCX202404)。
文摘This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.1)Mo_(0.05)O_(3-δ)(B S CNM_(0.05)),Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.05)Mo_(0.1)O_(3-δ)(BSCNM_(0.1)),and Ba_(0.6)Sr_(0.4)Co_(0.85)Mo_(0.15)O_(3-δ)(BSCM)—with Mo doping contents of 5mol%,10mol%,and15mol%,respectively,were successfully prepared using the sol-gel method.The effects of Mo doping on the crystal structure,conductivity,thermal expansion coefficient,oxygen reduction reaction(ORR)activity,and electrochemical performance were systematically evaluated using X-ray diffraction analysis,thermally induced characterization,electrochemical impedance spectroscopy,and single-cell performance tests.The results revealed that Mo doping could improve the conductivity of the materials,suppress their thermal expansion effects,and significantly improve the electrochemical performance.Surface chemical state analysis using X-ray photoelectron spectroscopy revealed that 5mol%Mo doping could facilitate a high adsorbed oxygen concentration leading to enhanced ORR activity in the materials.Density functional theory calculations confirmed that Mo doping promoted the ORR activity in the materials.At an operating temperature of 600℃,the BSCNM_(0.05)cathode material exhibited significantly enhanced electrochemical impedance characteristics,with a reduced area specific resistance of 0.048Ω·cm~2,which was lower than that of the undoped BSCN matrix material by 32.39%.At the same operating temperature,an anode-supported single cell using a BSCNM_(0.05)cathode achieved a peak power density of 1477 mW·cm^(-2),which was 30.71%,56.30%,and 171.50%higher than those of BSCN,BSCNM_(0.1),and B SCM,respectively.The improved ORR activity and electrochemical performance of BSCNM_(0.05)indicate that it can be used as a cathode material in low-temperature solid oxide fuel cells.
