Non-precious metal cobalt-based oxide inevitably dissolves for acid oxygen evolution reaction(OER).Designing an efficient deposition channel for leaching cobalt species is a promising approach.The dissolution-depositi...Non-precious metal cobalt-based oxide inevitably dissolves for acid oxygen evolution reaction(OER).Designing an efficient deposition channel for leaching cobalt species is a promising approach.The dissolution-deposition equilibrium of Co is achieved by doping Mn in the lattice of LaCo_(1-x)Mn_(x)O_(3),prolonging the lifespan in acidic conditions by 14 times.The lattice doping of Mn produces a strain that enhances the adsorption capacity of OH^(-).The self-catalysis of Mn causes the leaching Co to be deposited in the form of CoO_(2),which ensures that the long-term stability of LaCo_(1-x)Mn_(x)O_(3)is 70 h instead of 5 h for LaCoO_(3).Mn doping enhances the deprotonation of^(*)OOH→O_(2)in acidic environments.Notably,the over-potential of optimized LaCo_(1-x)Mn_(x)O_(3)is 345 mV at 10 mA cm^(-2)for acidic OER.This work presents a promising method for developing noble metal-free catalysts that enhance the acidic OER activity and stability.展开更多
Y_(3)Al_(2)Ga_(3)O_(12):Ce^(3+),Cr^(3+)(YAGG:Ce^(3+),Cr^(3+)),as a persistent luminescent material,has advantages of high initial luminescence intensity and long persistent time,which is promising in persistent lumine...Y_(3)Al_(2)Ga_(3)O_(12):Ce^(3+),Cr^(3+)(YAGG:Ce^(3+),Cr^(3+)),as a persistent luminescent material,has advantages of high initial luminescence intensity and long persistent time,which is promising in persistent luminescent material applications.At present,YAGG:Ce^(3+),Cr^(3+)powders exhibit good persistent performance,but their persistent performance of ceramics still needs to be further improved to meet the new requirements.In this work,(Y_(0.998)Ce_(0.002))_(3)(Al_(1-x)Cr_(x))_(2)Ga_(3)O_(12) ceramics with different Cr^(3+)doping concentrations were prepared by solid-state reaction,including air pre-sintering,hot isostatic pressing(HIP)post-treatment and air annealing,to investigate the effects of Cr^(3+)doping concentration on the microstructure,optical properties and persistent performance of the ceramics.The results showed that as the doping concentration of Cr^(3+)increased from 0.025%to 0.2%(in atom),no significant effect of Cr^(3+)concentration on the morphology of pre-sintered ceramics or HIP post-treatment ceramics was observed,but the in-line transmittance gradually increased while the persistent performance gradually decreased.Among them,YAGG:Ce^(3+),Cr^(3+)ceramics doped with 0.025%Cr^(3+)showed the strongest initial luminescence intensity exceeding 6055 mcd/m^(2) and a persistent time of 1030 min after air pre-sintering combined with HIP post-treatment and air annealing.By optimizing the Cr^(3+)doping concentration and the fabrication process,the persistent luminescence(PersL)performance of the YAGG:Ce^(3+),Cr^(3+)ceramics was obviously improved.展开更多
The development of cost-effective and highly stable electrocatalysts for oxygen evolution reactions holds paramount importance in practical hydrogen production.Herein,we present a novel self-supported electrode compri...The development of cost-effective and highly stable electrocatalysts for oxygen evolution reactions holds paramount importance in practical hydrogen production.Herein,we present a novel self-supported electrode comprising Ce-doped Ni-Fe-Se nanosheets grown on carbon cloth(Ni-Fe-Ce-Se/CC).This electrode was synthesized through a selenylation process,utilizing Ni-Fe-Ce-layered double hydroxide/carbon cloth(Ni-Fe-Ce LDH/CC)as the precursor.Notably,Ni-Fe-Ce-Se/CC electrode demonstrates remarkable performance,requiring a low overpotential of 300 mV to attain a current density of 100 mA·cm^(-2)under harsh alkaline conditions.Furthermore,the electrode exhibits exceptional stability during continuous operation for 100 h.Insight into the underlying mechanisms was gained through a combination of experimental results and density functional theory calculations.Our findings reveal that Ce doping induces crystal structure deformation in Ni-Fe-Se and enhances electron enrichment around Ni atoms.This structural modification optimizes the adsorption energy of oxygen-based intermediates on the Ni-Fe-Se surface.This work offers a valuable strategy for regulating the electron transfer and adsorption capabilities of transition metal selenide electrocatalysts through RE atoms doping,opening new avenues for enhanced electrocatalytic performance.展开更多
Na_(3)V_(2)O_(2x)(PO_(4))_(2)F_(3-2x)(NVPOF)is considered one of the most promising cathode materials for sodium-ion batteries due to its favorable working potential and optimal theoretical specific capacity.However,i...Na_(3)V_(2)O_(2x)(PO_(4))_(2)F_(3-2x)(NVPOF)is considered one of the most promising cathode materials for sodium-ion batteries due to its favorable working potential and optimal theoretical specific capacity.However,its long-cycle and rate performance are significantly constrained by the low Na^(+)electronic conductivity of NVPOF.Furthermore,the prevalent self-discharge phenomenon restricts its applicability in practical applications.In this paper,the cathode material Na_(3)V_(1.84)Fe_(0.16)(PO_(4))_(2)F_(3)(x=0.16)was synthesized by quantitatively introducing Fe^(3+)into the V-site of NVPOF.The introduction of Fe^(3+)significantly reduced the original bandgap and the energy barrier of NVPOF,as demonstrated through density functional theory calculations(DFT).When material x=0.16 is employed as the cathode material for the sodium-ion battery,the Na^(+)diffusion coefficient is significantly enhanced,exhibiting a lower activation energy of42.93 kJ mol^(-1).Consequently,material x=0.16 exhibits excellent electrochemical performance(rate capacity:57.32 mA h g^(-1)@10 C,cycling capacity:the specific capacity of 101.3 mA h g^(-1)can be stably maintained after 1000 cycles at 1 C current density).It can also achieve a full charge state in only2.39 min at a current density of 10 C while maintaining low energy loss across various stringent self-discharge tests.In addition,the sodium storage mechanism associated with the three-phase transition of Na_(X)V_(1.84)Fe_(0.16)(PO_(4))_(2)F_(3)(X=1,2,3)was elucidated by a series of experiments.In conclusion,this study presents a novel approach to multifunctional advanced sodium-ion battery cathode materials.展开更多
Designing cathode possessing crystalline@amorphous core-shell structure with both active core and shell is a meaningful work for resolving the low specific capacity,unstable cycling performance and sluggish reaction ki...Designing cathode possessing crystalline@amorphous core-shell structure with both active core and shell is a meaningful work for resolving the low specific capacity,unstable cycling performance and sluggish reaction kinetics issues of rechargeable magnesium batteries(RMBs)by providing more active sites as well as releasing inner stress during cycling.Herein,WO_(3)@WO_(3-x)S_(x) owning crystalline@amorphous core-shell structure containing both active core and active shell is constructed successfully by introducing S into metastable WO3 structure under temperaturefield applying.In such structure,amorphous shell would provide continuous Mg^(2+)diffusion channels due to its isotropy property for most Mg^(2+)migrating rapidly to interface and then adsorb at ions reservoir formed by interfacial electricfield for increasing specific capacity.It also makes security for stable structure of WO_(3)@WO_(3-x)S_(x) by alleviating volume expansion of crystalline core WO_(3) during cycling to prolong cycling life.Additionally,“softer”ions S^(2-)would weaken interaction between hard acid Mg^(2+) and ionic lattice to enhance Mg^(2+)storage kinetics.Therefore,WO_(3)@WO_(3-x)S_(x) delivers the superior cycling performance(1000 cycles with 83.3%),rate capability(88.5 mAh g^(-1) at 1000 mA g^(-1))and specific capacity(about 150 mAh g^(-1) at 50 mA g^(-1)),which is near 2 times higher than that of WO3.It is believed that the crystalline@amorphous core-shell structure with both active core and shell designing via doping strategy is enlightening for the development of high-performance RMBs,and such design can be extended to other energy storage devices for better electrochemical performance.展开更多
Mn^(2+)-doped CsPbCl_(3)(Mn^(2+):CsPbCl_(3)) nanocrystals(NCs) have attracted considerable attention due to their unique strong and broad orange-red emission band,presenting promising applications in the field of phot...Mn^(2+)-doped CsPbCl_(3)(Mn^(2+):CsPbCl_(3)) nanocrystals(NCs) have attracted considerable attention due to their unique strong and broad orange-red emission band,presenting promising applications in the field of photoelectric devices.However,pristine Mn^(2+):CsPbCl_(3)NCs commonly suffer from low photoluminescence quantum yield(PL QY) and stability issues.Herein,we introduced europium ions(Eu^(3+))into Mn^(2+):CsPbCl_(3)NCs via the thermal injection synthesis method to obtain high performance Eu^(3+)and Mn^(2+)codoped CsPbCl_(3)(Eu^(3+)/Mn^(2+):CsPbCl_(3)) NCs.The maximum PL QY of the resulting Eu^(3+)/Mn^(2+):CsPbCl_(3)NCs reaches up to 90.92%.It is found that the doping of Eu^(3+)ions significantly reduces the non-radiative recombination caused by high defect states,and improves the energy transfer efficiency from exciton to Mn^(2+),thereby boosting the PL performance.Moreover,doping Eu^(3+)ions notably improves the UV-light and water stability of Mn^(2+):CsPbCl_(3)NCs.We further demonstrate the application versatility of Eu^(3+)/Mn^(2+):CsPbCl_(3)NCs in white light emitting diodes(WLEDs) and optical anticounterfeiting applications.This work provides a valuable perspective for the attainment of high performance Mn^(2+):CsPbCl_(3)NCs and lays a foundation for the codoping of other lanthanide ions to adjust the luminescence properties of Mn^(2+):CsPbCl_(3)NCs.展开更多
Doping modification is one of the most effective ways to optimize the thermoelectric properties of Bi_(2)Te_(3)-based alloys.P-type Bi_(2−x)Sb_(x)Te_(3) thermoelectric materials have been successfully prepared by dire...Doping modification is one of the most effective ways to optimize the thermoelectric properties of Bi_(2)Te_(3)-based alloys.P-type Bi_(2−x)Sb_(x)Te_(3) thermoelectric materials have been successfully prepared by direct Sb doping method.It can be found that doping Sb into Bi_(2)Te_(3) lattice array for Bi-site replacement facilitates the generation of Sb′Te anti-site defects.This anti-site defects can increase the hole concentration and optimize electrical transport properties of Bi_(2−x)Sb_(x)Te_(3) alloys.In addition,the point defects induced by mass and stress fluctuations and the Sb impurities produced during the sintering process can enhance the multi-scale phonon scattering and reduce the lattice thermal conductivity.As a result,the Bi_(0.47)Sb_(1.63)Te_(3) sample has a maximum thermoelectric figure of merit ZT of 1.04 at 350 K.It is worth noting that the bipolar effect of Bi_(2)Te_(3)-based alloys can be weakened with the increase of Sb content.The Bi_(0.44)Sb_(1.66)Te_(3) sample has a maximum average ZT value(0.93)in the temperature range of 300–500 K,indicating that direct doping of Sb can broaden the temperature range corresponding to the optimal ZT value.This work provides an idea for developing high-performance near room temperature thermoelectric materials with a wide temperature range.展开更多
This work studied the magnetic,dielectric,and mechanical parameters of lanthanum doped cobalt-magnesium ferrite nanoparticles Co_(0.5)Mg_(0.5)La_(x)Fe_(2-x)O4(CMLF)prepared by citrate combustion route.Fourier transfor...This work studied the magnetic,dielectric,and mechanical parameters of lanthanum doped cobalt-magnesium ferrite nanoparticles Co_(0.5)Mg_(0.5)La_(x)Fe_(2-x)O4(CMLF)prepared by citrate combustion route.Fourier transform infrared spectroscopy(FTIR)spectra show lower band(v_(2))at 391-386 cm^(-1) and upper band(v_(1))at 572-570 cm^(-1),which demonstrate the cubic spinel structure formation for all CMLF nanoferrites.Magnetic parameters such as saturation magnetization,remanent magnetization,coer-civity,magnetic moment,anisotropy constant,and initial permittivity were investigated using a vibrating sample magnetometer(VSM).The sample Co_(0.5)Mg_(0.5)La_(0.03)Fe_(1.97)O4 has the optimal saturation magnetization of 47.78 emu/g,whereas the sample Co_(0.5)Mg_(0.5)La_(0.15)Fe_(1.85)O4 has a maximum coercivity of 1031 Oe.The dielectric constant,dielectric loss tangent,ac conductivity and impedance(Z)were also investigated with the addition of La ions.With La doping,the dielectric loss value decreases with 52%compared to the pristine sample,indicating it to be a potential candidate for high frequency appli-cations.The ac conductivity graphs exhibit adherence to Jonscher's single power law,indicating that the conduction process is primarily driven by the small polaron tunneling mechanism.Analytical investigation was conducted on the impedance spectroscopy and electric modulus for the CMLF nanoferrites.The nanoferrite Co_(0.5)Mg_(0.5)La_(0.15)Fe_(1.9)O_(4)has the optimum longitudinal modulus(4.60 GPa),shear modulus(0.85 GPa),Young's modulus(2.37 GPa),and bulk modulus(3.46 GPa)compared tothepristine sample.展开更多
Poly(3-hexylthiophene)(P3HT)is one of the most promising hole-transporting materials in the pursuit of efficient and stable perovskite solar cells due to its outstanding stability and low cost.However,the intrinsic lo...Poly(3-hexylthiophene)(P3HT)is one of the most promising hole-transporting materials in the pursuit of efficient and stable perovskite solar cells due to its outstanding stability and low cost.However,the intrinsic low carrier density of P3 HT and poor contact between the P3HT/perovskite interface always lead to a low performance of the solar cell,while conventional chemical doping always makes the films unstable and limits the scalability.In this work,for the first time,we simultaneously enhanced the hole transporting properties of P3HT film and the interface of perovskite by doping it with a judiciously designed oxidized small molecule organic semiconductor.The organic salt not only can promote the lamellar crystallinity of P3HT to obtain better charge transport properties,but also reduce the defects of perovskite.As a result,we achieved champion efficiencies of 23.0%for small-area solar cells and 18.8%for larger-area modules(48.0 cm^(2)).This efficiency is the highest value for P3HT-based perovskite modules.Moreover,the solar cells show excellent operational stability,retaining over 95%of their initial efficiencies after1200 h of continuous operation.展开更多
Mg_(3)Bi_(2)-based flms are promising near-room-temperature thermoelectric materials for the development of fexible thermoelectric devices.However,the high hole concentration caused by the abundance of intrinsic Mg va...Mg_(3)Bi_(2)-based flms are promising near-room-temperature thermoelectric materials for the development of fexible thermoelectric devices.However,the high hole concentration caused by the abundance of intrinsic Mg vacancies easily leads to deterioration of electrical properties,especially for p-type Mg_(3)Bi_(2) flm.And the optimization of thermal conductivity of the Mg_(3)Bi_(2)-based flms is barely investigated.In this work,we demonstrate the improved thermoelectric performances of p-type Mg_(3)Bi_(2) through Ag doping by magnetron sputtering.This doping successfully reduces the hole concentration and broadens the band gap of Mg_(3)Bi_(2),thus resulting in a peak power factor of 442μW m−1 K−2 at 525 K.At the same time,Ag doping-induced fuctuations in mass and microscopic strain efectively enhanced the phonon scattering to reduce the lattice thermal conductivity.Consequently,a maximum thermoelectric fgure of merit of 0.22 is achieved at 525 K.Its near-roomtemperature thermoelectric performances demonstrate superior performance compared to many Mg_(3)Bi_(2)-based flms.To further evaluate its potential for thermoelectric power generation,we fabricated a thermoelectric device using Ag-doped Mg_(3)Bi_(2) flms,which achieved a power density of 864μW cm⁻2 at 35 K temperature diference.This study presents an efective strategy for the advancement of Mg_(3)Bi_(2)-based flms for application in micro-thermoelectric devices.展开更多
LiNiO_(2)(LNO)is one of the most promising cathode materials for lithium-ion batteries.Tungsten element in enhancing the stability of LNO has been researched extensively.However,the understanding of the specific dopin...LiNiO_(2)(LNO)is one of the most promising cathode materials for lithium-ion batteries.Tungsten element in enhancing the stability of LNO has been researched extensively.However,the understanding of the specific doping process and existing form of W are still not perfect.This study proposes a lithium-induced grain boundary phase W doping mechanism.The results demonstrate that the introduced W atomsfirst react with the lithium source to generate a Li–W–O phase at the grain boundary of primary particles.With the increase of lithium ratio,W atoms gradually diffuse from the grain boundary phase to the interior layered structure to achieve W doping.The feasibility of grain boundary phase doping is verified byfirst principles calculation.Furthermore,it is found that the Li2WO4 grain boundary phase is an excellent lithium ion conductor,which can protect the cathode surface and improve the rate performance.The doped W can alleviate the harmful H2↔H3 phase transition,thereby inhibiting the generation of microcracks,and improving the electrochemical performance.Consequently,the 0.3 wt%W-doped sample provides a significant improved capacity retention of 88.5%compared with the pristine LNO(80.7%)after 100 cycles at 2.8–4.3 V under 1C.展开更多
By manipulating the distribution of surface electrons,defect engineering enables effective control over the adsorption energy between adsorbates and active sites in the CO_(2)reduction reaction(CO_(2)RR).Herein,we rep...By manipulating the distribution of surface electrons,defect engineering enables effective control over the adsorption energy between adsorbates and active sites in the CO_(2)reduction reaction(CO_(2)RR).Herein,we report a hollow indium oxide nanotube containing both oxygen vacancy and sulfur doping(V_o-Sx-In_(2)O_(3))for improved CO_(2)-to-HCOOH electroreduction and Zn-CO_(2)battery.The componential synergy significantly reduces the*OCHO formation barrier to expedite protonation process and creates a favorable electronic micro-environment for*HCOOH desorption.As a result,the CO_(2)RR performance of Vo-Sx-In_(2)O_(3)outperforms Pure-In_(2)O_(3)and V_o-In_(2)O_(3),where V_o-S53-In_(2)O_(3)exhibits a maximal HCOOH Faradaic efficiency of 92.4%at-1,2 V vs.reversible hydrogen electrode(RHE)in H-cell and above 92%over a wide window potential with high current density(119.1 mA cm^(-2)at-1.1 V vs.RHE)in flow cell.Furthermore,the rechargeable Zn-CO_(2)battery utilizing V_o-S53-In_(2)O_(3)as cathode shows a high power density of 2.29 mW cm^(-2)and a long-term stability during charge-discharge cycles.This work provides a valuable perspective to elucidate co-defective catalysts in regulating the intermediates for efficient CO_(2)RR.展开更多
Electrocatalytic hydrogen production from seawater holds enormous promise for clean energy generation.Nevertheless,the direct electrolysis of seawater encounters significant challenges due to poor anodic stability cau...Electrocatalytic hydrogen production from seawater holds enormous promise for clean energy generation.Nevertheless,the direct electrolysis of seawater encounters significant challenges due to poor anodic stability caused by detrimental chlorine chemistry.Herein,we present our recent discovery that the incorporation of Ce into Ni Fe layered double hydroxide nanosheet array on Ni foam(Ce-Ni Fe LDH/NF)emerges as a robust electrocatalyst for seawater oxidation.During the seawater oxidation process,CeO_(2)is generated,effectively repelling Cl^(-)and inhibiting the formation of Cl O-,resulting in a notable enhancement in the oxidation activity and stability of alkaline seawater.The prepared Ce-Ni Fe LDH/NF requires only overpotential of 390 m V to achieve the current density of 1 A cm^(-2),while maintaining long-term stability for 500 h,outperforming the performance of Ni Fe LDH/NF(430 m V,150 h)by a significant margin.This study highlights the effectiveness of a Ce-doping strategy in augmenting the activity and stability of materials based on Ni Fe LDH in seawater electrolysis for oxygen evolution.展开更多
Li_(3)PO_(4)@Li_(0.99)K_(0.01)Ni_(0.83)Co_(0.11)Mn_(O.06)O_(2)(NCM-KP) cathode powders are synthesized via K^(+)doping in calcination processes and H_3PO_4 coating in sol-gel processes.K^(+) precisely enters into the ...Li_(3)PO_(4)@Li_(0.99)K_(0.01)Ni_(0.83)Co_(0.11)Mn_(O.06)O_(2)(NCM-KP) cathode powders are synthesized via K^(+)doping in calcination processes and H_3PO_4 coating in sol-gel processes.K^(+) precisely enters into the lattice to widen the(003) plane to 0.4746 nm with a lower cationic disordered degree of 1.87%.Moreover,the surface residual lithium salts are treated by H_3PO_4 to generate a uniform Li_(3)PO_(4) coating layer of approximately 11.41 nm,which completely covers on the surface of secondary spherical particles to improve the interfacial stability.At 25℃,the NCM-KP electrode delivers a discharge specific capacity of 148.9 mAh·g^(-1) with a remarkable capacity retention ratio of 84.1% after 200 cycles at 1.0C and retains a high reversible specific capacity of 154.4 mAh·g^(-1) at 5.0C.Even at 1.0C and 60℃,it can maintain a reversible discharge specific capacity of 114.6 mAh·g^(-1) with 0.21% of capacity decay per cycle after 200 cycles,which is significantly lower than 0.40% for the pristine NCM powders.Importantly,the charge transfer resistance of 238.89 Ω for the NCM-KP electrode is significantly lower than 947.41 Ω for the pristine NCM one by restricting the interfacial side reactions.Therefore,combining K+doping and Li_(3)PO_(4) coating is an effective strategy to enable the significant improvement of the electrochemical property of high-nickel cathode materials,which may be mainly attributed to the widened diffusion pathway and the formed Li_(3)PO_(4) protective layer,thus promoting Li~+diffusion rate and preventing the erosion of HF.展开更多
Solid-state electrolytes with high oxidation stability are crucial for achieving high power density allsolid-state lithium batteries.Halide electrolytes are promising candidates due to their outstanding compatibility ...Solid-state electrolytes with high oxidation stability are crucial for achieving high power density allsolid-state lithium batteries.Halide electrolytes are promising candidates due to their outstanding compatibility with cathode materials and high Li^(+)conductivity.However,the electrochemical stability of chloride electrolytes is still limited,leaving them unsuitable for ultrahigh voltage operation.Besides,chemical compatibility issue between sulfide and halide electrolytes affects the electrochemical performance of all-solid-state batteries.Herein,Li-ion conductor Li_(3+x)InCl_(6-x)O_(x) is designed to address these challenges.Li_(3.25)InCl_(5.75)O_(0.25)shows a Li-ion conductivity of 0.90 mS cm^(-1)at room temperature,a high onset oxidation voltage of 3.84 V,fewer by-products at ultrahigh operation voltage,and good chemical compatibility with Li_(5.5)PS_(4.5)Cl_(1.5).The Li_(3.25)InCl_(5.75)O_(0.25)@LiNi_(0.7)Co_(0.1)Mn_(0.2)O_(2)-Li_(3.25)InCl_(5.75)O_(0.25)-VGCF/Li_(3.25)InCl_(5.75)O_(0.25)/Li_(5.5)PS_(4.5)Cl_(1.5)/Li-In battery delivers good electrochemical performances at high operating voltage.This work provides a simple,economical,and effective strategy for designing high-voltage all-solid-state electrolytes.展开更多
Sodium with low cost and high abundance is considered as a substitute element of lithium for batteries and supercapacitors,which need the appropriate host materials to accommodate the relatively large Na^(+) ions.Comp...Sodium with low cost and high abundance is considered as a substitute element of lithium for batteries and supercapacitors,which need the appropriate host materials to accommodate the relatively large Na^(+) ions.Compared to Li^(+) storage,Na^(+) storage makes higher demands on the structural optimization of perovskite bismuth ferrite(BiFeO_(3)).We propose a novel strategy of defect engineering on BiFeO_(3) through Na and V codoping for high-efficiency Na^(+) storage,to reveal the roles of oxygen vacancies and V ions played in the enhanced electrochemical energy storage performances of Na-ion capacitors.The formation of the oxygen vacancies in the Na and V codoped BiFeO_(3)(denoted as NV-BFO),is promoted by Na doping and suppressed by V doping,which can be demonstrated by XPS and EPR spectra.By the first-principles calculations,the oxygen vacancies and V ions in NV-BFO are confirmed to substantially lower the Na^(+)migration energy barriers through the space and electric field effects,to effectively promote the Na^(+) transport in the crystals.Electrochemical kinetic analysis of the NV-BFO//NV-BFO capacitors indicates the dominant capacitive-controlled capacity,which depends on fast Na^(+) deintercalation-intercalation process in the NV-BFO electrode.The NV-BFO//NV-BFO capacitors open up a new avenue for developing highperformance Na-ion capacitors.展开更多
To investigate the enhancing effect of Mn on the performance of simultaneous catalytic oxidation of AsH_(3)and PH_(3)by CuO-Al_(2)O_(3)in a reducing atmosphere under micro-oxygen conditions,Cu-Mn modifiedγ-Al_(2)O_(3...To investigate the enhancing effect of Mn on the performance of simultaneous catalytic oxidation of AsH_(3)and PH_(3)by CuO-Al_(2)O_(3)in a reducing atmosphere under micro-oxygen conditions,Cu-Mn modifiedγ-Al_(2)O_(3)catalysts were prepared.The characteristics of the catalysts showed that Mn reduced the crystallinity of the active CuO component,increased the number of oxygen vacancies and acidic sites on the catalyst surface,enhanced the mobility of surface oxygen,and the interaction between copper and manganese promoted the redox cycling ability of the catalysts and improved their oxidation performance,which increased the conversion frequency(TOF)by 2.54×10^(-2)to 3.07×10^(-2)sec^(-1).On the other hand,the introduction of Mn reduced the production of phosphate and As_(2)O_(3)on the catalyst surface by30.96%and 44.9%,which reduced the coverage and inerting of the active sites by phosphate and As_(2)O_(3),resulting in an 8 hr(6 hr)improvement in the stability of PH_(3)(AsH_(3))removal.展开更多
The surface/interfacial reactivity of clay is a critical factor influencing the sedimentation of coal slurry water.To achieve efficient sedimentation of coal slurry water,this paper introduces a novel approach that re...The surface/interfacial reactivity of clay is a critical factor influencing the sedimentation of coal slurry water.To achieve efficient sedimentation of coal slurry water,this paper introduces a novel approach that regulates the hydrophobicity of defective active sites in clay minerals.Fe^(3+)-doped kaolinite(Fe^(3+)-Kao)was synthesized by hydrothermal methods.Subsequently,tests were conducted on the adsorption capacity,surface wettability,and agglomeration sedimentation of alkyl amine/ammonium salts(AAS)on Fe^(3+)-Kao surfaces.Fe^(3+)doping significantly enhances AAS adsorption and alters surface properties from hydrophilic to hydrophobic,promoting kaolinite particle aggregation and sedimentation,thereby improving coal slurry water treatment efficiency.Molecular dynamics(MD)simulations were performed to analyze the statistical adsorption behavior of AAS on Fe^(3+)-Kao surfaces.The simulation results indicate that the mechanism by which Fe^(3+)doping influences the hydrophobic regulation of kaolinite surfaces is due to the enhanced interfacial interactions between the kaolinite surface and AAS,where the interfacial effects are more pronounced on surfaces closer to the dopant sites.The findings of this research offer valuable insights for future studies on other types of lattice defects in clay minerals,as well as for the development of more efficient treatment chemicals for coal slurry water.展开更多
Potassium-ion batteries(PIBs)offer a cost-effective and resource-abundant solution for large-scale energy storage.However,the progress of PIBs is impeded by the lack of high-capacity,long-life,and fast-kinetics anode ...Potassium-ion batteries(PIBs)offer a cost-effective and resource-abundant solution for large-scale energy storage.However,the progress of PIBs is impeded by the lack of high-capacity,long-life,and fast-kinetics anode electrode materials.Here,we propose a dual synergic optimization strategy to enhance the K^(+)storage stability and reaction kinetics of Bi_(2)S_(3) through two-dimensional compositing and cation doping.Externally,Bi_(2)S_(3) nanoparticles are loaded onto the surface of three-dimensional interconnected Ti_(3)C_(2)T_(x) nanosheets to stabilize the electrode structure.Internally,Cu^(2+)doping acts as active sites to accelerate K^(+)storage kinetics.Various theoretical simulations and ex situ techniques are used to elucidate the external–internal dual synergism.During discharge,Ti_(3)C_(2)T_(x) and Cu^(2+)collaboratively facilitate K+intercalation.Subsequently,Cu^(2+)doping primarily promotes the fracture of Bi2S3 bonds,facilitating a conversion reaction.Throughout cycling,the Ti_(3)C_(2)T_(x) composite structure and Cu^(2+)doping sustain functionality.The resulting Cu^(2+)-doped Bi2S3 anchored on Ti_(3)C_(2)T_(x)(C-BT)shows excellent rate capability(600 mAh g^(-1) at 0.1 A g^(–1);105 mAh g^(-1) at 5.0 A g^(-1))and cycling performance(91 mAh g^(-1) at 5.0 A g^(-1) after 1000 cycles)in half cells and a high energy density(179 Wh kg–1)in full cells.展开更多
基金financially supported by the Shandong Provincial Natural Science Foundation(ZR2023LFG005)the National Natural Science Foundation of China(Nos.22479161,52274308 and U22B20144)the Fundamental Research Funds for the Central Universities(No.24CX03012A)。
文摘Non-precious metal cobalt-based oxide inevitably dissolves for acid oxygen evolution reaction(OER).Designing an efficient deposition channel for leaching cobalt species is a promising approach.The dissolution-deposition equilibrium of Co is achieved by doping Mn in the lattice of LaCo_(1-x)Mn_(x)O_(3),prolonging the lifespan in acidic conditions by 14 times.The lattice doping of Mn produces a strain that enhances the adsorption capacity of OH^(-).The self-catalysis of Mn causes the leaching Co to be deposited in the form of CoO_(2),which ensures that the long-term stability of LaCo_(1-x)Mn_(x)O_(3)is 70 h instead of 5 h for LaCoO_(3).Mn doping enhances the deprotonation of^(*)OOH→O_(2)in acidic environments.Notably,the over-potential of optimized LaCo_(1-x)Mn_(x)O_(3)is 345 mV at 10 mA cm^(-2)for acidic OER.This work presents a promising method for developing noble metal-free catalysts that enhance the acidic OER activity and stability.
基金National Key R&D Program of China(2023YFB3506600)。
文摘Y_(3)Al_(2)Ga_(3)O_(12):Ce^(3+),Cr^(3+)(YAGG:Ce^(3+),Cr^(3+)),as a persistent luminescent material,has advantages of high initial luminescence intensity and long persistent time,which is promising in persistent luminescent material applications.At present,YAGG:Ce^(3+),Cr^(3+)powders exhibit good persistent performance,but their persistent performance of ceramics still needs to be further improved to meet the new requirements.In this work,(Y_(0.998)Ce_(0.002))_(3)(Al_(1-x)Cr_(x))_(2)Ga_(3)O_(12) ceramics with different Cr^(3+)doping concentrations were prepared by solid-state reaction,including air pre-sintering,hot isostatic pressing(HIP)post-treatment and air annealing,to investigate the effects of Cr^(3+)doping concentration on the microstructure,optical properties and persistent performance of the ceramics.The results showed that as the doping concentration of Cr^(3+)increased from 0.025%to 0.2%(in atom),no significant effect of Cr^(3+)concentration on the morphology of pre-sintered ceramics or HIP post-treatment ceramics was observed,but the in-line transmittance gradually increased while the persistent performance gradually decreased.Among them,YAGG:Ce^(3+),Cr^(3+)ceramics doped with 0.025%Cr^(3+)showed the strongest initial luminescence intensity exceeding 6055 mcd/m^(2) and a persistent time of 1030 min after air pre-sintering combined with HIP post-treatment and air annealing.By optimizing the Cr^(3+)doping concentration and the fabrication process,the persistent luminescence(PersL)performance of the YAGG:Ce^(3+),Cr^(3+)ceramics was obviously improved.
基金supported by the National Key Technology R&D Program of China(Nos.2021YFB3500801,2022YFB3504302 and 2022YFC3901503)the Natural Science Foundation and Overseas Talent Projects of Jiangxi Province(Nos.0232BAB214025 and 20232BCJ25044)the Double Thousand Plan of Jiangxi Province(No.jxsq2023201002).
文摘The development of cost-effective and highly stable electrocatalysts for oxygen evolution reactions holds paramount importance in practical hydrogen production.Herein,we present a novel self-supported electrode comprising Ce-doped Ni-Fe-Se nanosheets grown on carbon cloth(Ni-Fe-Ce-Se/CC).This electrode was synthesized through a selenylation process,utilizing Ni-Fe-Ce-layered double hydroxide/carbon cloth(Ni-Fe-Ce LDH/CC)as the precursor.Notably,Ni-Fe-Ce-Se/CC electrode demonstrates remarkable performance,requiring a low overpotential of 300 mV to attain a current density of 100 mA·cm^(-2)under harsh alkaline conditions.Furthermore,the electrode exhibits exceptional stability during continuous operation for 100 h.Insight into the underlying mechanisms was gained through a combination of experimental results and density functional theory calculations.Our findings reveal that Ce doping induces crystal structure deformation in Ni-Fe-Se and enhances electron enrichment around Ni atoms.This structural modification optimizes the adsorption energy of oxygen-based intermediates on the Ni-Fe-Se surface.This work offers a valuable strategy for regulating the electron transfer and adsorption capabilities of transition metal selenide electrocatalysts through RE atoms doping,opening new avenues for enhanced electrocatalytic performance.
基金supported by the National Natural Science Foundation of China(22075227)the Shaanxi Fundamental Science Research Project for Chemistry and Biology(23JHQ011)。
文摘Na_(3)V_(2)O_(2x)(PO_(4))_(2)F_(3-2x)(NVPOF)is considered one of the most promising cathode materials for sodium-ion batteries due to its favorable working potential and optimal theoretical specific capacity.However,its long-cycle and rate performance are significantly constrained by the low Na^(+)electronic conductivity of NVPOF.Furthermore,the prevalent self-discharge phenomenon restricts its applicability in practical applications.In this paper,the cathode material Na_(3)V_(1.84)Fe_(0.16)(PO_(4))_(2)F_(3)(x=0.16)was synthesized by quantitatively introducing Fe^(3+)into the V-site of NVPOF.The introduction of Fe^(3+)significantly reduced the original bandgap and the energy barrier of NVPOF,as demonstrated through density functional theory calculations(DFT).When material x=0.16 is employed as the cathode material for the sodium-ion battery,the Na^(+)diffusion coefficient is significantly enhanced,exhibiting a lower activation energy of42.93 kJ mol^(-1).Consequently,material x=0.16 exhibits excellent electrochemical performance(rate capacity:57.32 mA h g^(-1)@10 C,cycling capacity:the specific capacity of 101.3 mA h g^(-1)can be stably maintained after 1000 cycles at 1 C current density).It can also achieve a full charge state in only2.39 min at a current density of 10 C while maintaining low energy loss across various stringent self-discharge tests.In addition,the sodium storage mechanism associated with the three-phase transition of Na_(X)V_(1.84)Fe_(0.16)(PO_(4))_(2)F_(3)(X=1,2,3)was elucidated by a series of experiments.In conclusion,this study presents a novel approach to multifunctional advanced sodium-ion battery cathode materials.
基金supported by the National Natural Science Foundation of China under Grant No.52072196,52002200,52102106,52202262,22379081,22379080,Major Basic Research Program of Natural Science Foundation of Shandong Province under Grant No.ZR2020ZD09the Natural Science Foundation of Shandong Province under Grant No.ZR2020QE063,ZR202108180009,ZR2023QE059the Postdoctoral Program in Qingdao under No.QDBSH20220202019.
文摘Designing cathode possessing crystalline@amorphous core-shell structure with both active core and shell is a meaningful work for resolving the low specific capacity,unstable cycling performance and sluggish reaction kinetics issues of rechargeable magnesium batteries(RMBs)by providing more active sites as well as releasing inner stress during cycling.Herein,WO_(3)@WO_(3-x)S_(x) owning crystalline@amorphous core-shell structure containing both active core and active shell is constructed successfully by introducing S into metastable WO3 structure under temperaturefield applying.In such structure,amorphous shell would provide continuous Mg^(2+)diffusion channels due to its isotropy property for most Mg^(2+)migrating rapidly to interface and then adsorb at ions reservoir formed by interfacial electricfield for increasing specific capacity.It also makes security for stable structure of WO_(3)@WO_(3-x)S_(x) by alleviating volume expansion of crystalline core WO_(3) during cycling to prolong cycling life.Additionally,“softer”ions S^(2-)would weaken interaction between hard acid Mg^(2+) and ionic lattice to enhance Mg^(2+)storage kinetics.Therefore,WO_(3)@WO_(3-x)S_(x) delivers the superior cycling performance(1000 cycles with 83.3%),rate capability(88.5 mAh g^(-1) at 1000 mA g^(-1))and specific capacity(about 150 mAh g^(-1) at 50 mA g^(-1)),which is near 2 times higher than that of WO3.It is believed that the crystalline@amorphous core-shell structure with both active core and shell designing via doping strategy is enlightening for the development of high-performance RMBs,and such design can be extended to other energy storage devices for better electrochemical performance.
基金Project supported by the National Natural Science Foundation of China (12174075)the Scientific and Technological Bases and Talents of Guangxi (Guike AD21220016)+1 种基金Guangxi Science and Technology Major Project(AA23073018)the special fund for Guangxi Bagui Scholars。
文摘Mn^(2+)-doped CsPbCl_(3)(Mn^(2+):CsPbCl_(3)) nanocrystals(NCs) have attracted considerable attention due to their unique strong and broad orange-red emission band,presenting promising applications in the field of photoelectric devices.However,pristine Mn^(2+):CsPbCl_(3)NCs commonly suffer from low photoluminescence quantum yield(PL QY) and stability issues.Herein,we introduced europium ions(Eu^(3+))into Mn^(2+):CsPbCl_(3)NCs via the thermal injection synthesis method to obtain high performance Eu^(3+)and Mn^(2+)codoped CsPbCl_(3)(Eu^(3+)/Mn^(2+):CsPbCl_(3)) NCs.The maximum PL QY of the resulting Eu^(3+)/Mn^(2+):CsPbCl_(3)NCs reaches up to 90.92%.It is found that the doping of Eu^(3+)ions significantly reduces the non-radiative recombination caused by high defect states,and improves the energy transfer efficiency from exciton to Mn^(2+),thereby boosting the PL performance.Moreover,doping Eu^(3+)ions notably improves the UV-light and water stability of Mn^(2+):CsPbCl_(3)NCs.We further demonstrate the application versatility of Eu^(3+)/Mn^(2+):CsPbCl_(3)NCs in white light emitting diodes(WLEDs) and optical anticounterfeiting applications.This work provides a valuable perspective for the attainment of high performance Mn^(2+):CsPbCl_(3)NCs and lays a foundation for the codoping of other lanthanide ions to adjust the luminescence properties of Mn^(2+):CsPbCl_(3)NCs.
基金supported by the Anhui Province Natural Science Foundation for Excellent Youth Scholars(2208085Y17)the University Synergy Innovation Program of Anhui Province(GXXT-2022-008+1 种基金GXXT-2021-022)the Anhui Key Lab of Metal Material and Processing Open Project.
文摘Doping modification is one of the most effective ways to optimize the thermoelectric properties of Bi_(2)Te_(3)-based alloys.P-type Bi_(2−x)Sb_(x)Te_(3) thermoelectric materials have been successfully prepared by direct Sb doping method.It can be found that doping Sb into Bi_(2)Te_(3) lattice array for Bi-site replacement facilitates the generation of Sb′Te anti-site defects.This anti-site defects can increase the hole concentration and optimize electrical transport properties of Bi_(2−x)Sb_(x)Te_(3) alloys.In addition,the point defects induced by mass and stress fluctuations and the Sb impurities produced during the sintering process can enhance the multi-scale phonon scattering and reduce the lattice thermal conductivity.As a result,the Bi_(0.47)Sb_(1.63)Te_(3) sample has a maximum thermoelectric figure of merit ZT of 1.04 at 350 K.It is worth noting that the bipolar effect of Bi_(2)Te_(3)-based alloys can be weakened with the increase of Sb content.The Bi_(0.44)Sb_(1.66)Te_(3) sample has a maximum average ZT value(0.93)in the temperature range of 300–500 K,indicating that direct doping of Sb can broaden the temperature range corresponding to the optimal ZT value.This work provides an idea for developing high-performance near room temperature thermoelectric materials with a wide temperature range.
文摘This work studied the magnetic,dielectric,and mechanical parameters of lanthanum doped cobalt-magnesium ferrite nanoparticles Co_(0.5)Mg_(0.5)La_(x)Fe_(2-x)O4(CMLF)prepared by citrate combustion route.Fourier transform infrared spectroscopy(FTIR)spectra show lower band(v_(2))at 391-386 cm^(-1) and upper band(v_(1))at 572-570 cm^(-1),which demonstrate the cubic spinel structure formation for all CMLF nanoferrites.Magnetic parameters such as saturation magnetization,remanent magnetization,coer-civity,magnetic moment,anisotropy constant,and initial permittivity were investigated using a vibrating sample magnetometer(VSM).The sample Co_(0.5)Mg_(0.5)La_(0.03)Fe_(1.97)O4 has the optimal saturation magnetization of 47.78 emu/g,whereas the sample Co_(0.5)Mg_(0.5)La_(0.15)Fe_(1.85)O4 has a maximum coercivity of 1031 Oe.The dielectric constant,dielectric loss tangent,ac conductivity and impedance(Z)were also investigated with the addition of La ions.With La doping,the dielectric loss value decreases with 52%compared to the pristine sample,indicating it to be a potential candidate for high frequency appli-cations.The ac conductivity graphs exhibit adherence to Jonscher's single power law,indicating that the conduction process is primarily driven by the small polaron tunneling mechanism.Analytical investigation was conducted on the impedance spectroscopy and electric modulus for the CMLF nanoferrites.The nanoferrite Co_(0.5)Mg_(0.5)La_(0.15)Fe_(1.9)O_(4)has the optimum longitudinal modulus(4.60 GPa),shear modulus(0.85 GPa),Young's modulus(2.37 GPa),and bulk modulus(3.46 GPa)compared tothepristine sample.
基金financially supported by the National Natural Science Foundation of China(52472248 and 22075221)the Key Research and Development Project of Shanxi Province(202202060301003 and 202202060301015)the Innovation Program of Wuhan-Shuguang Project(2023010201020367)。
文摘Poly(3-hexylthiophene)(P3HT)is one of the most promising hole-transporting materials in the pursuit of efficient and stable perovskite solar cells due to its outstanding stability and low cost.However,the intrinsic low carrier density of P3 HT and poor contact between the P3HT/perovskite interface always lead to a low performance of the solar cell,while conventional chemical doping always makes the films unstable and limits the scalability.In this work,for the first time,we simultaneously enhanced the hole transporting properties of P3HT film and the interface of perovskite by doping it with a judiciously designed oxidized small molecule organic semiconductor.The organic salt not only can promote the lamellar crystallinity of P3HT to obtain better charge transport properties,but also reduce the defects of perovskite.As a result,we achieved champion efficiencies of 23.0%for small-area solar cells and 18.8%for larger-area modules(48.0 cm^(2)).This efficiency is the highest value for P3HT-based perovskite modules.Moreover,the solar cells show excellent operational stability,retaining over 95%of their initial efficiencies after1200 h of continuous operation.
基金supported by the National Natural Science Foundation of China(Nos.52073290 and 51927803)the Science Fund for Distinguished Young Scholars of Liaoning Province(No.2023JH6/100500004)the Shenyang Science and Technology Plan Project(No.23-407-3-23).
文摘Mg_(3)Bi_(2)-based flms are promising near-room-temperature thermoelectric materials for the development of fexible thermoelectric devices.However,the high hole concentration caused by the abundance of intrinsic Mg vacancies easily leads to deterioration of electrical properties,especially for p-type Mg_(3)Bi_(2) flm.And the optimization of thermal conductivity of the Mg_(3)Bi_(2)-based flms is barely investigated.In this work,we demonstrate the improved thermoelectric performances of p-type Mg_(3)Bi_(2) through Ag doping by magnetron sputtering.This doping successfully reduces the hole concentration and broadens the band gap of Mg_(3)Bi_(2),thus resulting in a peak power factor of 442μW m−1 K−2 at 525 K.At the same time,Ag doping-induced fuctuations in mass and microscopic strain efectively enhanced the phonon scattering to reduce the lattice thermal conductivity.Consequently,a maximum thermoelectric fgure of merit of 0.22 is achieved at 525 K.Its near-roomtemperature thermoelectric performances demonstrate superior performance compared to many Mg_(3)Bi_(2)-based flms.To further evaluate its potential for thermoelectric power generation,we fabricated a thermoelectric device using Ag-doped Mg_(3)Bi_(2) flms,which achieved a power density of 864μW cm⁻2 at 35 K temperature diference.This study presents an efective strategy for the advancement of Mg_(3)Bi_(2)-based flms for application in micro-thermoelectric devices.
基金supported by the National Natural Science Foundation of China(No.52122407,No.52174285,52404317)the Science and Technology Innovation Program of Hunan Province(No.2022RC3048).
文摘LiNiO_(2)(LNO)is one of the most promising cathode materials for lithium-ion batteries.Tungsten element in enhancing the stability of LNO has been researched extensively.However,the understanding of the specific doping process and existing form of W are still not perfect.This study proposes a lithium-induced grain boundary phase W doping mechanism.The results demonstrate that the introduced W atomsfirst react with the lithium source to generate a Li–W–O phase at the grain boundary of primary particles.With the increase of lithium ratio,W atoms gradually diffuse from the grain boundary phase to the interior layered structure to achieve W doping.The feasibility of grain boundary phase doping is verified byfirst principles calculation.Furthermore,it is found that the Li2WO4 grain boundary phase is an excellent lithium ion conductor,which can protect the cathode surface and improve the rate performance.The doped W can alleviate the harmful H2↔H3 phase transition,thereby inhibiting the generation of microcracks,and improving the electrochemical performance.Consequently,the 0.3 wt%W-doped sample provides a significant improved capacity retention of 88.5%compared with the pristine LNO(80.7%)after 100 cycles at 2.8–4.3 V under 1C.
基金supported by the Fundamental Research Funds for the Central Universities(22120230104).
文摘By manipulating the distribution of surface electrons,defect engineering enables effective control over the adsorption energy between adsorbates and active sites in the CO_(2)reduction reaction(CO_(2)RR).Herein,we report a hollow indium oxide nanotube containing both oxygen vacancy and sulfur doping(V_o-Sx-In_(2)O_(3))for improved CO_(2)-to-HCOOH electroreduction and Zn-CO_(2)battery.The componential synergy significantly reduces the*OCHO formation barrier to expedite protonation process and creates a favorable electronic micro-environment for*HCOOH desorption.As a result,the CO_(2)RR performance of Vo-Sx-In_(2)O_(3)outperforms Pure-In_(2)O_(3)and V_o-In_(2)O_(3),where V_o-S53-In_(2)O_(3)exhibits a maximal HCOOH Faradaic efficiency of 92.4%at-1,2 V vs.reversible hydrogen electrode(RHE)in H-cell and above 92%over a wide window potential with high current density(119.1 mA cm^(-2)at-1.1 V vs.RHE)in flow cell.Furthermore,the rechargeable Zn-CO_(2)battery utilizing V_o-S53-In_(2)O_(3)as cathode shows a high power density of 2.29 mW cm^(-2)and a long-term stability during charge-discharge cycles.This work provides a valuable perspective to elucidate co-defective catalysts in regulating the intermediates for efficient CO_(2)RR.
基金support from the Free Exploration Project of Frontier Technology for Laoshan Laboratory(No.16-02)the National Natural Science Foundation of China(Nos.22072015 and 21927811)。
文摘Electrocatalytic hydrogen production from seawater holds enormous promise for clean energy generation.Nevertheless,the direct electrolysis of seawater encounters significant challenges due to poor anodic stability caused by detrimental chlorine chemistry.Herein,we present our recent discovery that the incorporation of Ce into Ni Fe layered double hydroxide nanosheet array on Ni foam(Ce-Ni Fe LDH/NF)emerges as a robust electrocatalyst for seawater oxidation.During the seawater oxidation process,CeO_(2)is generated,effectively repelling Cl^(-)and inhibiting the formation of Cl O-,resulting in a notable enhancement in the oxidation activity and stability of alkaline seawater.The prepared Ce-Ni Fe LDH/NF requires only overpotential of 390 m V to achieve the current density of 1 A cm^(-2),while maintaining long-term stability for 500 h,outperforming the performance of Ni Fe LDH/NF(430 m V,150 h)by a significant margin.This study highlights the effectiveness of a Ce-doping strategy in augmenting the activity and stability of materials based on Ni Fe LDH in seawater electrolysis for oxygen evolution.
基金financially supported by the National Natural Science Foundation of China (Nos.52274292 and 51874046)the Outstanding Youth Foundation of Hubei Province (No.2020CFA090)。
文摘Li_(3)PO_(4)@Li_(0.99)K_(0.01)Ni_(0.83)Co_(0.11)Mn_(O.06)O_(2)(NCM-KP) cathode powders are synthesized via K^(+)doping in calcination processes and H_3PO_4 coating in sol-gel processes.K^(+) precisely enters into the lattice to widen the(003) plane to 0.4746 nm with a lower cationic disordered degree of 1.87%.Moreover,the surface residual lithium salts are treated by H_3PO_4 to generate a uniform Li_(3)PO_(4) coating layer of approximately 11.41 nm,which completely covers on the surface of secondary spherical particles to improve the interfacial stability.At 25℃,the NCM-KP electrode delivers a discharge specific capacity of 148.9 mAh·g^(-1) with a remarkable capacity retention ratio of 84.1% after 200 cycles at 1.0C and retains a high reversible specific capacity of 154.4 mAh·g^(-1) at 5.0C.Even at 1.0C and 60℃,it can maintain a reversible discharge specific capacity of 114.6 mAh·g^(-1) with 0.21% of capacity decay per cycle after 200 cycles,which is significantly lower than 0.40% for the pristine NCM powders.Importantly,the charge transfer resistance of 238.89 Ω for the NCM-KP electrode is significantly lower than 947.41 Ω for the pristine NCM one by restricting the interfacial side reactions.Therefore,combining K+doping and Li_(3)PO_(4) coating is an effective strategy to enable the significant improvement of the electrochemical property of high-nickel cathode materials,which may be mainly attributed to the widened diffusion pathway and the formed Li_(3)PO_(4) protective layer,thus promoting Li~+diffusion rate and preventing the erosion of HF.
基金supported by the National Key Research and Development Program of China(2021YFB2500200)the National Natural Science Foundation of China(52177214,52222703)for supporting our workJiangsu Funding Program for Excellent Postdoctoral Talent for the support。
文摘Solid-state electrolytes with high oxidation stability are crucial for achieving high power density allsolid-state lithium batteries.Halide electrolytes are promising candidates due to their outstanding compatibility with cathode materials and high Li^(+)conductivity.However,the electrochemical stability of chloride electrolytes is still limited,leaving them unsuitable for ultrahigh voltage operation.Besides,chemical compatibility issue between sulfide and halide electrolytes affects the electrochemical performance of all-solid-state batteries.Herein,Li-ion conductor Li_(3+x)InCl_(6-x)O_(x) is designed to address these challenges.Li_(3.25)InCl_(5.75)O_(0.25)shows a Li-ion conductivity of 0.90 mS cm^(-1)at room temperature,a high onset oxidation voltage of 3.84 V,fewer by-products at ultrahigh operation voltage,and good chemical compatibility with Li_(5.5)PS_(4.5)Cl_(1.5).The Li_(3.25)InCl_(5.75)O_(0.25)@LiNi_(0.7)Co_(0.1)Mn_(0.2)O_(2)-Li_(3.25)InCl_(5.75)O_(0.25)-VGCF/Li_(3.25)InCl_(5.75)O_(0.25)/Li_(5.5)PS_(4.5)Cl_(1.5)/Li-In battery delivers good electrochemical performances at high operating voltage.This work provides a simple,economical,and effective strategy for designing high-voltage all-solid-state electrolytes.
基金financial supports from National Natural Science Foundation of China(22005174 and 52271133)。
文摘Sodium with low cost and high abundance is considered as a substitute element of lithium for batteries and supercapacitors,which need the appropriate host materials to accommodate the relatively large Na^(+) ions.Compared to Li^(+) storage,Na^(+) storage makes higher demands on the structural optimization of perovskite bismuth ferrite(BiFeO_(3)).We propose a novel strategy of defect engineering on BiFeO_(3) through Na and V codoping for high-efficiency Na^(+) storage,to reveal the roles of oxygen vacancies and V ions played in the enhanced electrochemical energy storage performances of Na-ion capacitors.The formation of the oxygen vacancies in the Na and V codoped BiFeO_(3)(denoted as NV-BFO),is promoted by Na doping and suppressed by V doping,which can be demonstrated by XPS and EPR spectra.By the first-principles calculations,the oxygen vacancies and V ions in NV-BFO are confirmed to substantially lower the Na^(+)migration energy barriers through the space and electric field effects,to effectively promote the Na^(+) transport in the crystals.Electrochemical kinetic analysis of the NV-BFO//NV-BFO capacitors indicates the dominant capacitive-controlled capacity,which depends on fast Na^(+) deintercalation-intercalation process in the NV-BFO electrode.The NV-BFO//NV-BFO capacitors open up a new avenue for developing highperformance Na-ion capacitors.
基金supported by the National Natural Science Foundation of China (Nos.51868030,52070090,52100122,22266019,and 21876071)the Science and Technology Planning Project of Yunnan Province (Nos.202001AU070031,202101BE070001-030,and 202101BC070001-009)Applied Basic Research Program of Yunnan Province (No.2019FD043)。
文摘To investigate the enhancing effect of Mn on the performance of simultaneous catalytic oxidation of AsH_(3)and PH_(3)by CuO-Al_(2)O_(3)in a reducing atmosphere under micro-oxygen conditions,Cu-Mn modifiedγ-Al_(2)O_(3)catalysts were prepared.The characteristics of the catalysts showed that Mn reduced the crystallinity of the active CuO component,increased the number of oxygen vacancies and acidic sites on the catalyst surface,enhanced the mobility of surface oxygen,and the interaction between copper and manganese promoted the redox cycling ability of the catalysts and improved their oxidation performance,which increased the conversion frequency(TOF)by 2.54×10^(-2)to 3.07×10^(-2)sec^(-1).On the other hand,the introduction of Mn reduced the production of phosphate and As_(2)O_(3)on the catalyst surface by30.96%and 44.9%,which reduced the coverage and inerting of the active sites by phosphate and As_(2)O_(3),resulting in an 8 hr(6 hr)improvement in the stability of PH_(3)(AsH_(3))removal.
基金supported by the National key research and development Program of China(No.2023YFE0100600)the National Natural Science Foundation of China(Nos.52174233 and 52474282)the Natural Science Research Project of Anhui Educational Committee(No.2022AH030083)。
文摘The surface/interfacial reactivity of clay is a critical factor influencing the sedimentation of coal slurry water.To achieve efficient sedimentation of coal slurry water,this paper introduces a novel approach that regulates the hydrophobicity of defective active sites in clay minerals.Fe^(3+)-doped kaolinite(Fe^(3+)-Kao)was synthesized by hydrothermal methods.Subsequently,tests were conducted on the adsorption capacity,surface wettability,and agglomeration sedimentation of alkyl amine/ammonium salts(AAS)on Fe^(3+)-Kao surfaces.Fe^(3+)doping significantly enhances AAS adsorption and alters surface properties from hydrophilic to hydrophobic,promoting kaolinite particle aggregation and sedimentation,thereby improving coal slurry water treatment efficiency.Molecular dynamics(MD)simulations were performed to analyze the statistical adsorption behavior of AAS on Fe^(3+)-Kao surfaces.The simulation results indicate that the mechanism by which Fe^(3+)doping influences the hydrophobic regulation of kaolinite surfaces is due to the enhanced interfacial interactions between the kaolinite surface and AAS,where the interfacial effects are more pronounced on surfaces closer to the dopant sites.The findings of this research offer valuable insights for future studies on other types of lattice defects in clay minerals,as well as for the development of more efficient treatment chemicals for coal slurry water.
基金This work received financial support from the National Natural Science Foundation of China(Grant Nos.U23A20574,52250010,and 52201242)the 261 Project MIIT,the Young Elite Scientists Sponsorship Program by CAST(Grant No.2021QNRC001)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.2242022R40018)the Jiangsu Funding Program for Excellent Postdoctoral Talent(Grant No.2022ZB75).
文摘Potassium-ion batteries(PIBs)offer a cost-effective and resource-abundant solution for large-scale energy storage.However,the progress of PIBs is impeded by the lack of high-capacity,long-life,and fast-kinetics anode electrode materials.Here,we propose a dual synergic optimization strategy to enhance the K^(+)storage stability and reaction kinetics of Bi_(2)S_(3) through two-dimensional compositing and cation doping.Externally,Bi_(2)S_(3) nanoparticles are loaded onto the surface of three-dimensional interconnected Ti_(3)C_(2)T_(x) nanosheets to stabilize the electrode structure.Internally,Cu^(2+)doping acts as active sites to accelerate K^(+)storage kinetics.Various theoretical simulations and ex situ techniques are used to elucidate the external–internal dual synergism.During discharge,Ti_(3)C_(2)T_(x) and Cu^(2+)collaboratively facilitate K+intercalation.Subsequently,Cu^(2+)doping primarily promotes the fracture of Bi2S3 bonds,facilitating a conversion reaction.Throughout cycling,the Ti_(3)C_(2)T_(x) composite structure and Cu^(2+)doping sustain functionality.The resulting Cu^(2+)-doped Bi2S3 anchored on Ti_(3)C_(2)T_(x)(C-BT)shows excellent rate capability(600 mAh g^(-1) at 0.1 A g^(–1);105 mAh g^(-1) at 5.0 A g^(-1))and cycling performance(91 mAh g^(-1) at 5.0 A g^(-1) after 1000 cycles)in half cells and a high energy density(179 Wh kg–1)in full cells.
