Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,a...Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,and 8 wt.%)on the wettability and interfacial reaction between the alloy and shell were investigated by a sessile-drop experiment.The results show that increasing the Al_(2)O_(3) doping contents(0−8 wt.%)reduces the porosity(21.74%−10.08%)and roughness(3.22−1.34μm)of the shell surface.The increase in Cr_(2)O_(3) dopant content(2−8 wt.%)further exacerbates the interfacial reaction,leading to an increase in the thickness of the reaction layer(2.6−3.1μm)and a decrease in the wetting angle(93.9°−91.0°).The addition of Al_(2)O_(3) and TiO_(2) dopants leads to the formation of Al_(2)TiO_(5) composite oxides in the reaction products,which effectively inhibits the interfacial reaction.The increase in TiO_(2) dopant contents(0−8 wt.%)further promotes the formation of Al_(2)TiO_(5),which decreases the thickness of the interfacial reaction layer(3.9−1.2μm)and increases the wetting angle(95.0°−103.8°).The introduced dopants enhance the packing density of the shell surface,while simultaneously suppress the diffusion of active metal elements from the alloy matrix to the interface.展开更多
Exploiting non-precious metal catalysts with excellent oxygen reduction reaction(ORR)performance for energy devices is paramount essential for the green and sustainable society development.Herein,low-cost,high-perform...Exploiting non-precious metal catalysts with excellent oxygen reduction reaction(ORR)performance for energy devices is paramount essential for the green and sustainable society development.Herein,low-cost,high-performance biomass-derived ORR catalysts with an asymmetric Fe-N_(3)P configuration was prepared by a simple pyrolysis-etching technique,where carboxymethyl cellulose(CMC)was used as the carbon source,urea and 1,10-phenanthroline iron complex(FePhen)as additives,and Na_(3)PO_(4)as the phosphorus dopant and a pore-forming agent.The CMC-derived FeNPC catalyst displayed a large specific area(BET:1235 m^(2)g^(-1))with atomically dispersed Fe-N_(3)P active sites,which exhibited superior ORR activity and stability in alkaline solution(E_(1/2)=0.90 V vs.RHE)and Zn-air batteries(P_(max)=149 mW cm^(-2))to commercial Pt/C catalyst(E_(1/2)=0.87 V,P_(max)=118 mW cm^(-2))under similar experimental conditions.This work provides a feasible and costeffective route toward highly efficient ORR catalysts and their application to Zn-air batteries for energy conversion.展开更多
High temperature piezoelectric energy harvester(HTPEH)is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors.However,simultaneously excellent performances,inclu...High temperature piezoelectric energy harvester(HTPEH)is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors.However,simultaneously excellent performances,including high figure of merit(FOM),insulation resistivity(ρ)and depolarization temperature(Td)are indispensable but hard to achieve in lead-free piezoceramics,especially operating at 250°C has not been reported before.Herein,well-balanced performances are achieved in BiFeO3–BaTiO3 ceramics via innovative defect engineering with respect to delicate manganese doping.Due to the synergistic effect of enhancing electrostrictive coefficient by polarization configuration optimization,regulating iron ion oxidation state by high valence manganese ion and stabilizing domain orientation by defect dipole,comprehensive excellent electrical performances(Td=340°C,ρ250°C>10^(7)Ωcm and FOM_(250°C)=4905×10^(–15)m^(2)N^(−1))are realized at the solid solubility limit of manganese ions.The HT-PEHs assembled using the rationally designed piezoceramic can allow for fast charging of commercial electrolytic capacitor at 250°C with high energy conversion efficiency(η=11.43%).These characteristics demonstrate that defect engineering tailored BF-BT can satisfy high-end HT-PEHs requirements,paving a new way in developing selfpowered wireless sensors working in HT environments.展开更多
In this paper,low-temperature dielectric-blocked discharge plasma(DBD)was employed for the first time to treat silica-doped H_(4)PMo_(11)VO_(40)(HPAV)catalysts(DBD(Ar/x)-MF-Catal)and apply them in the catalytic methac...In this paper,low-temperature dielectric-blocked discharge plasma(DBD)was employed for the first time to treat silica-doped H_(4)PMo_(11)VO_(40)(HPAV)catalysts(DBD(Ar/x)-MF-Catal)and apply them in the catalytic methacrolein(MAL)selective oxidation to produce methacrylic acid(MAA).This work investigates in detail the controllable regulation of the concentration of oxidation states on silica-doped HPAV catalysts by adjusting the DBD discharge with controlled changes in voltage,current,treatment time,and treatment medium.It reports the intrinsic correlation between oxidation states and MAL oxidation performance.The research results indicated that the catalytic performance was related to the presence of oxygen vacancies and oxygen species(VO^(2+)),and are the main reason for the selective oxidation of MAL to MAA.Besides,the generation of oxygen vacancies and VO^(2+)altered localized electrons,which resulted in the easier activation of O_(2).Theoretical calculations of DFT also proved the formation mechanism of oxygen vacancies and VO^(2+)and electron properties on high-performance polymers,which elucidated the intrinsic influence of catalyst components.The DBD(Ar/10)-MF-Catal catalysts with suitable VO^(2+)and oxygen vacancy concentrations exhibited the highest catalytic performance with 90%MAL conversion and 70%MAA selectivity and showed good stability(500 h).展开更多
In this study,a catalyst was synthesized using a two-step in-situ molecular beam epitaxy method to grow H_(4)PMo_(11)VO_(40)(HPAV)on amination-treated SiO_(2) nanoparticles,which served as both dopant and host agents....In this study,a catalyst was synthesized using a two-step in-situ molecular beam epitaxy method to grow H_(4)PMo_(11)VO_(40)(HPAV)on amination-treated SiO_(2) nanoparticles,which served as both dopant and host agents.SiO_(2) dopant was modified with(3-aminopropyl)triethoxysilane(APTS),facilitating the formation of ammonium ions that enhanced the overall positive charge.This modification enabled the effective dispersion and exposure of HPAV's active species and induced a structural transformation of HPAV from a triclinic to a cubic crystal phase.The two-step hosting growth process optimized the proportions of Cs^(+),H^(+)and NH_(4)^(+)antinuclear ions,thereby fine-tuning the synergistic catalysis of oxidation and acidity,as well as the oxidative sensitivity at HPAV catalytic interface.The resultant 8(HPAV)&4(Cs_(3)PAV)-NH_(2)-SiO_(2) catalyst achieved a methacrolein(MAL)conversion rate of 84%and a methacrylic acid(MAA)selectivity of 71%.Even after 10.5 h of reaction time,the catalyst retained its high dispersion,cubic crystal structure,and Keggin configuration,demonstrating stable catalytic performance over a continuous 200-h reaction period.展开更多
Doping plays a pivotal role in enhancing the performance of organic semiconductors(OSCs)for advanced optoelectronic and thermoelectric applications.In this study,we systematically investigated the doping performance a...Doping plays a pivotal role in enhancing the performance of organic semiconductors(OSCs)for advanced optoelectronic and thermoelectric applications.In this study,we systematically investigated the doping performance and applicability of the ionic dopant 4-isopropyl-4′-methyldiphenyliodonium tetrakis(penta-fluorophenyl-borate)(DPI-TPFB)as a p-dopant for OSCs.Using the p-type OSC PBBT-2T as a model system,we demonstrated that DPI-TPFB shows significant doping effect,as confirmed by ESR spectra,ultraviolet-visible-near-infrared(UV-vis-NIR)absorption,and work function analysis,and enhances the electronic conductivity of PBBT-2T films by over four orders of magnitude.Furthermore,DPI-TPFB exhibited broad doping applicability,effectively doping various p-type OSCs and even imparting p-type characteristics to the n-type OSC N2200,transforming its intrinsic n-type behavior into p-type.The application of DPI-TPFB-doped PBBT-2T films in organic thermoelectric devices(OTEs)was also explored,achieving a power factor of approximately 10μW·m^(-1)·K^(-2).These findings highlight the potential of DPI-TPFB as a versatile and efficient dopant for integration into organic optoelectronic and thermoelectric devices.展开更多
Fe–Ga sheets with large magnetostriction are required for improving the conversion efficiency under the ultra-high frequencymagnetic field. Trace Tb element doping can simultaneously improve the magnetostriction and ...Fe–Ga sheets with large magnetostriction are required for improving the conversion efficiency under the ultra-high frequencymagnetic field. Trace Tb element doping can simultaneously improve the magnetostriction and ductility of Fe–Ga alloy. However, the im-pact of trace Tb doping on the microstructure and magnetostriction of Fe–Ga thin sheets is an open question. In this paper, the effects oftrace Tb addition on the secondary recrystallization and magnetostriction of Fe–Ga thin sheets are systematically studied by comparing thecharacteristics evolution of precipitation, texture, and nanoinclusions. The results indicate that trace Tb addition accelerates the secondaryrecrystallization of Goss texture due to the combined action of the bimodal size distributed precipitates, smaller grains, and more HEGBsin primary recrystallization. After quenching at 900℃, the magnetostriction value in 0.07 at %Tb-doped Fe_(81)Ga_(19) thin sheets increases by 30% to that of Fe_(81)Ga_(19) thin sheets. The increase in magnetostriction is attributed to the decrease in the number of Tb-rich precipitates andthe higher density of the nanometer-sized modified-D0_(3) inclusions induced by the dissolving of trace Tb elements after quenching. Theseresults demonstrate a simple and efficient approach for preparing Fe–Ga thin sheets with a large magnetostrictive coefficient by a combin-ation of trace RE element addition and conventional rolling method.展开更多
Oxygen-rich porous carbons are promising candidates for the carbon-based cathodes of zinc ion hybrid capacitors(ZIHCs).Potassium activation is a traditional and effective way to prepare oxygen-rich porous carbons.Effi...Oxygen-rich porous carbons are promising candidates for the carbon-based cathodes of zinc ion hybrid capacitors(ZIHCs).Potassium activation is a traditional and effective way to prepare oxygen-rich porous carbons.Efficient potassium activation is the key to develop high-performance oxygen-rich porous carbon cathodes.Herein,the alkali lignin,extracted from eucalyptus wood by geopolymer-assisted low-alkali pretreatment,is used to prepare oxygen-rich lignin-derived porous carbons(OLPCs)through KOH activation and K_(2)CO_(3)activation at 700-900℃.KOH activation constructs a hierarchical micro-mesoporous structure,while K_(2)CO_(3)activation constructs a microporous structure.Furthermore,K_(2)CO_(3)activation could more efficiently construct active oxygen(C=O)species than KOH activation.The OLPCs prepared by KOH/K_(2)CO_(3)activations at 800℃show the highest microporosity(78.4/87.7%)and C=O content(5.3/8.0 at.%).Due to that C=O and micropore adsorb zinc ions,the OLPCs prepared by K_(2)CO_(3)activation at 800℃with higher C=O content and microporosity deliver superior capacitive performance(256 F g^(-1)at 0.1 A g^(-1))than that by KOH activation at 800℃(224 F g^(-1)at 0.1 A g^(-1)),and excellent cycling stability.This work provides a new insight into the sustainable preparation of oxygenrich porous carbon cathodes through efficient potassium activation for ZIHCs.展开更多
Although lots of efforts have been devoted on new less hygroscopic dopants to address problems in hole transport materials(HTM),the long-time post-oxidation and the volatilization of 4-tert-butylpyridine(tBP)are still...Although lots of efforts have been devoted on new less hygroscopic dopants to address problems in hole transport materials(HTM),the long-time post-oxidation and the volatilization of 4-tert-butylpyridine(tBP)are still issues.A new doping mechanism for spiro-OMeTAD by disulfiram(TETD)is revealed in this work.Owing to its disulfide bond,TETD can be activated easily to produce reactive sulfur for the rapid oxidation of spiro-OMeTAD in the absence of oxygen with formation of[spiro-OMeTAD•]+[SC(S)N(C_(2)H_(5))_(2)]^(-).Thus,in this situation,the Li+ion has the opportunity to coordinate tBP and fix each other in HTM film.DFT calculations suggest that the resulting favorable energy(with a△E of−1.29 eV)must come from the mutual interactions among Li^(+),TFSI^(−),and tBP,which is different from the well-known doping process that tBP would not participate in the doping reaction.As a result,the introduction of a new radical into the HTM greatly reduce device performance fluctuations due to the environmental dependence and inhibit tBP volatilizing for enhanced long-term stability.展开更多
Aberration-corrected annular dark-field scanning transmission electron microscopy(ADF-STEM)is a powerful tool for structural and chemical analysis of materials.Conventional analyses of ADF-STEM images rely on human la...Aberration-corrected annular dark-field scanning transmission electron microscopy(ADF-STEM)is a powerful tool for structural and chemical analysis of materials.Conventional analyses of ADF-STEM images rely on human labeling,making them labor-intensive and prone to subjective error.Here,we introduce a deep-learning-based workflow combining a pix2pix network for image denoising and either a mathematical algorithm local intensity threshold segmentation(LITS)or another deep learning network UNet for chemical identification.After denoising,the processed images exhibit a five-fold improvement in signal-to-noise ratio and a 20%increase in accuracy of atomic localization.Then,we take atomic-resolution images of Y–Ce dual-atom catalysts(DACs)and Fe-doped ReSe_(2) nanosheets as examples to validate the performance.Pix2pix is applied to identify atomic sites in Y–Ce DACs with a location recall of 0.88 and a location precision of 0.99.LITS is used to further differentiate Y and Ce sites by the intensity of atomic sites.Furthermore,pix2pix and UNet workflow with better automaticity is applied to identification of Fe-doped ReSe_(2) nanosheets.Three types of atomic sites(Re,the substitution of Fe for Re,and the adatom of Fe on Re)are distinguished with the identification recall of more than 0.90 and the precision of higher than 0.93.These results suggest that this strategy facilitates high-quality and automated chemical identification of atomic-resolution images.展开更多
Doping small amounts at the A-site or B-site of SmCrO_(3)ceramics is a promising approach for modifying their microstructure,as well as their magnetic and dielectric properties.In this study,polycrystalline ceramics o...Doping small amounts at the A-site or B-site of SmCrO_(3)ceramics is a promising approach for modifying their microstructure,as well as their magnetic and dielectric properties.In this study,polycrystalline ceramics of Sm_(1-x)Ni_(x)CrO_(3)(x=0,0.05,and 0.20)and SmCr_(1-y)Ni_(y)O_(3)(y=0.05 and 0.20)were synthesized via a conventional solid-state reaction.X-ray diffraction validated that all the doped ceramics maintained an orthorhombic crystalline structure consistent with the Pbnm space group.Furthermore,X-ray photoelectron spectroscopy demonstrated the presence of Ni^(2+)ions in the doped specimens.Notably,doping resulted in significant enhancement of low-temperature magnetic properties,particularly in samples doped at the A-site,such as Sm0.80Ni0.20CrO_(3).Compared with the pristine sample,the maximum magnetization of Sm_(0.8)0Ni_(0.2)0CrO_(3)increased by approximately 60.9%and 93.5%in the zero-field cooling and field-cooling modes,respectively,in an external magnetic field of 100 Oe.Furthermore,the dielectric constants of the Ni-doped ceramics initially exceeded that of the pristine sample as the temperature increased.At equivalent doping ratios,A-site doping demonstrated superior performance over B-site doping,including higher magnetization,lower dielectric loss,and enhanced electrical quality factors.展开更多
Lithium salt-based hole transport layer(HTL)dopants commonly used in perovskite solar cells(PSCs)are known to negatively impact stability due to their intrinsic hygroscopic properties and ion migration.In this study,w...Lithium salt-based hole transport layer(HTL)dopants commonly used in perovskite solar cells(PSCs)are known to negatively impact stability due to their intrinsic hygroscopic properties and ion migration.In this study,we introduce an ammonium salt,p-methoxyphenylethylamine bis(trifluoromethyl)sulfoni mide(MPT),as a novel dual-function dopant for the HTL in PSCs.The chemical interaction between MPT and the widely used HTL material spiro-OMeTAD generates high concentrations of spiroOMeTAD^(+)radicals,effectively enhancing the doping of spiro-OMeTAD.Additionally,MPT reacts with the perovskite layer,forming a 2D perovskite structure at the perovskite/HTL interface,which passivates defects and suppresses interfacial ion migration.As a result,PSCs with MPT doping achieved a remarkable power conversion efficiency(PCE)of 25.52%for small-area devices(0.045 cm^(2))and 21.01%for mini-modules(16.8 cm^(2)).Moreover,the incorporation of MPT significantly enhances the moisture,light,and thermal stability of the PSCs by eliminating Li^(+)and suppressing I-migration.Notably,PSCs with MPT-doped PTAA retained 84%of their initial PCE after 1,300 h of aging at 60℃in a nitrogen-filled glovebox.Our work presents a unique doping strategy for the HTL in PSCs,offering a promising approach to simultaneously improve both the stability and efficiency of these devices.展开更多
Doping can optimize the magnetic and dielectric properties of SmCrO_(3),thereby expanding its application of electronic sensing,information storage and low-frequency capacitors.Herein,the ceramic composites of SmCrO_(...Doping can optimize the magnetic and dielectric properties of SmCrO_(3),thereby expanding its application of electronic sensing,information storage and low-frequency capacitors.Herein,the ceramic composites of SmCrO_(3),Sm_(1-x)Eu_(x)CrO_(3)(x=0.05 and 0.20)and SmCr_(1-y)Eu_(y)O_(3)(y=0.05 and 0.20)were prepared by traditional solid-state reaction.The pristine and Eu-doped SmCrO_(3)samples were characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM)and transmission electron microscopy(TEM).The characterization results confirm the uniform doping of Eu^(3+)into SmCrO_(3),with all compounds exhibiting an orthorhombic structure and good crystallinity.The temperature-dependent magnetization measurements show that doping does not change the Néel temperature(TN,197 K)and spin reorientation temperature(TSR,34 K)of all the Eu^(3+)doped SmCrO_(3)ceramics.Notably,the magnetization of Sm_(1-x)Eu_(x)CrO_(3)(x=0.05 and 0.20)increases with greater doping content,whereas the magnetization of SmCr_(1-y)Eu_(y)O_(3)(y=0.05,0.20)decreases with increased doping levels.The magnetizations of the Eu^(3+)doped SmCrO_(3)samples can be tuned between 0.54 and 0.79 emu·g^(-1)under 100 K and 20 kOe.The dielectric measurements illustrate that the doped samples exhibit higher dielectric constant and lower dielectric loss than those of pristine SmCrO_(3)at temperatures exceeding 300 K.This work presents a straightforward method for effectively modulating the magnetic and dielectric properties of SmCrO_(3).展开更多
To develop an efficient electrochemical CO_(2)reduction reaction(CO_(2)RR)for the production of C_(2)chemicals,improvements in the Cu catalyst are necessary.Doping is widely used for catalyst enhancement;however,only ...To develop an efficient electrochemical CO_(2)reduction reaction(CO_(2)RR)for the production of C_(2)chemicals,improvements in the Cu catalyst are necessary.Doping is widely used for catalyst enhancement;however,only a few elements have been examined.This study proposes guidelines for the selection of Cu catalyst dopants to promote ethylene production.It was hypothesized that the dopant chemical state highly influences the CO_(2)RR catalytic activity.In the case of dopants possessing a standard reduction potential within the CO_(2)RR potential region(e.g.,Mn and Ni),low Faradaic efficiency(FE)toward ethylene production was obtained owing to the presence of a metallic dopant(10.7%for Ni dopant).In contrast,a low standard reduction potential led to a stable high oxidation state for the dopant,yielding abundant Cu^(δ+)species with modified electronic structures and enhancing the CO_(2)RR catalytic activity for ethylene production(42.1%for Hf dopant).We expected that a dopant with a low standard reduction potential is difficult to reduce,which leads to a stable Cu-O-X bond and induces a stable Cu^(δ+)species.Our study provides insights into how to select dopant for various catalyst to enhance CO_(2)RR catalytic activity.展开更多
Optimizing the energy barrier of 2H-to-1T phase transformation plays a crucial role in modulating the intrinsic electronic structure of MoS_(2)to achieve satisfactory water-splitting performance,but remains a signific...Optimizing the energy barrier of 2H-to-1T phase transformation plays a crucial role in modulating the intrinsic electronic structure of MoS_(2)to achieve satisfactory water-splitting performance,but remains a significant challenge.Herein,we report a vacancy occupation-triggered phase transition strategy to fabricate a core-shell 1T phase nanorod structure,which is composed of S-vacancies decorated MoS_(2)as the core,and N,P co-doped carbons as the shell(1T-MoS_(2)@NPC).The co-insertion of N and P dopants into MoS_(2)can occupy partial S-vacancies,triggering a phase transformation from the semiconducting 2H phase to the conducting 1T phase with a reduced energy barrier.Profiting from the strong coupling effect between N,P dopants and S-vacancies,the as-made 1T-MoS_(2)@NPC exhibits excellent electrocatalytic activity for both HER(η_(10)=148 m V)and OER(η_(10)=232 mV)in alkaline solution.Meanwhile,a low cell voltage of 1.62 V is needed to drive a current density of 10mA cm^(-2)in 1.0 M KOH electrolyte.The theoretical calculation results reveal that the S-vacancies decorated C atoms in the meta-position relative to N,P atoms represent the most active HER and OER sites,which synergistically upshift the d band center and balance the rate-determining step,thus ensuring the simultaneous optimization of adsorption free energy and electronic structure.This vacancy-occupation-derived phase transformation strategy caused by non-metallic doping may provide valuable guidance for enhancing the performance of alkaline water electrolysis.展开更多
Tetravalent tin(Sn^(4+))-based inorganic perovskite semiconductors like Cs_(2)SnI_(6)are expected to replace lead-based perovskite counterparts due to advantages such as structural stability and environmental friendli...Tetravalent tin(Sn^(4+))-based inorganic perovskite semiconductors like Cs_(2)SnI_(6)are expected to replace lead-based perovskite counterparts due to advantages such as structural stability and environmental friendliness.In this paper,we reported the dopant compensation effect in the component-dependent self-doped(111)-oriented Cs_(2)SnI_(6)thin films grown with pulsed laser deposition(PLD)at room temperature.The films were grown on(100)-SrTiO_(3)(STO)substrates at room temperature by PLD.Hall results of the Cs_(2)SnI_(6)films with different components realizing by controlling the ratio of SnI_(4)/CsI in the targets demonstrate a clear change of conductivity type from N-type to P-type,while the carrier concentration decreases from 1018 to 1013 and accordingly the film resistivity increases significantly from 3.8 to 2506Ωcm.The defect-relatedopticalfingerprints of Cs_(2)SnI_(6)films werealsoinvestigated withtemperature-dependent photoluminescence spectroscopy.At low temperatures of 10 K,the Cs_(2)SnI_(6)films exhibit donor-bound(D^(0)X)and donor-acceptor pair(DAP)emission,respectively,due to the self-doping effect.These re-sults indicate that controlling the composition of the PLD target is a powerful way to tune the electrical properties of Cs_(2)SnI_(6)films for possible applications in solar cells or X-ray detectors.展开更多
Inverted perovskite solar cells(PSCs)have stood out in recent years for their great potential in offering low-temperature compatibility,long-term stability and tandem cell suitability.However,challenges persist,partic...Inverted perovskite solar cells(PSCs)have stood out in recent years for their great potential in offering low-temperature compatibility,long-term stability and tandem cell suitability.However,challenges persist,particularly concerning the use of nickel oxide nanoparticles(NiO_(x)NPs)as the hole transport material,where issues such as low conductivity,impurity-induced aggregation and interface redox reactions significantly hinder device performance.In response,this study presents a novel synthesis method for NiO_(x)NPs,leveraging the introduction of ammonium salt dopants(NH_(4)Cl and NH_(4)SCN),and the solar cell utilizing the doped NiO_(x)substrate exhibits much enhanced device performance.Furthermore,doped solar cells reach 23.27%power conversion efficiency(PCE)when a self-assembled monolayer(SAM)is further employed.This study provides critical insights into the synthesis and growth pathways of NiO_(x)NPs,propelling the development of efficient hole transport materials for high-performance PSCs.展开更多
In the direct drive inertial confinement fusion(ICF)scheme,a rippled interface between the ablator and the deuterium–tritium ice fuel can feed out and form perturbation seeds for the ablative Rayleigh–Taylor instabi...In the direct drive inertial confinement fusion(ICF)scheme,a rippled interface between the ablator and the deuterium–tritium ice fuel can feed out and form perturbation seeds for the ablative Rayleigh–Taylor instability,with undesirable effects.However,the evolution of this instability remains insufficiently studied,and the effects of high-Z dopant on this instability remain unclear.In this paper,we develop a theoretical model to calculate the feedout seeds and describe this instability.Our theory suggests that the feedout seeds are determined by the ablation pressure and the adiabatic index,while the subsequent growth depends mainly on the ablation velocity.Two-dimensional radiation hydrodynamic simulations confirm our theory.It is shown that targets with high-Z dopant in the outer ablator exhibit more severe feedout seeds,because of their higher ionization compared with undoped targets.The X-ray pre-ablation in high-Z doped targets significantly suppresses subsequent growth,leading to suppression of short-wavelength perturbations.However,for long-wavelength perturbations,this suppression is weakened,resulting in increased instability in high-Z doped targets.The results are helpful for understanding the innerinterface-initiated instability and the influence of high-Z dopant on it,providing valuable insights for target design and instability control in ICF.展开更多
Nanoscale Sb doped titanium dioxide thin films photocatalyst （Ti1-xSbO2） were obtained from dip-coating sol-gel method. The influence of dopant Sb density on the crystal structure and the phase transformation of the...Nanoscale Sb doped titanium dioxide thin films photocatalyst （Ti1-xSbO2） were obtained from dip-coating sol-gel method. The influence of dopant Sb density on the crystal structure and the phase transformation of the thin tilms were characterized by X-ray diffraction （XRD） and Raman spectra. The results of XRD showed that as prepared lilms were not only in anatase state but also in brookite. The crystalline size was estimated to be around 13.3-20 nm. Raman spectra indicated there coexisted other phases and a transformation from brookite to anatase in the samples doped with 0.2% Sb. After doping a proper amount of Sb, the cryst,allization rate and the content of the anatase Ti1-x, SbO2 in the thin films was clearly enhanced because Sb replaced part. of the Ti of TiO2 in the thin films. The anode current density （photocurrent density） and the first order reaction speed constant （k） of t.hin films doped with 0.2% Sb reached 42.49 μA/cm^2 and 0.171 h/cm^2 under 254 nm UV illumination, respectively, which is about 11 times and 2 times that of the non doped TiO2 anode prepared by the same method respectively.展开更多
The crystal of high concentration Nd:YAG was grown by flux method and diode pu mp microcavity laser was studied.High efficiency and frequency solid state lase r was built on research and development.some applications ...The crystal of high concentration Nd:YAG was grown by flux method and diode pu mp microcavity laser was studied.High efficiency and frequency solid state lase r was built on research and development.some applications such as target designa tion,laser radar,rangefinder,CATV etc. In order to maximize pump efficiency and power output,the Nd concentration shoul d be made as high as possible without degrading the gain through concentration q uenching.In crystal grown by Czochraski method.it is difficult to increase the N d concentration over 1.2% because of Nd segregation in the melt (yttrium aluminum garnet),which leads to large nonuniformities in doping.However,by using the f lux met hod growth technique,it is possible to grow uniformly doped crystal as much as 4 % Nd concentration YAG.展开更多
基金supported by the National Natural Science Foundation of China (No. 52374292)China Baowu Low Carbon Metallurgy Innovation Foundation, China (No. BWLCF202309)the Natural Science Foundation of Changsha City, China (No. KQ2208271)。
文摘Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,and 8 wt.%)on the wettability and interfacial reaction between the alloy and shell were investigated by a sessile-drop experiment.The results show that increasing the Al_(2)O_(3) doping contents(0−8 wt.%)reduces the porosity(21.74%−10.08%)and roughness(3.22−1.34μm)of the shell surface.The increase in Cr_(2)O_(3) dopant content(2−8 wt.%)further exacerbates the interfacial reaction,leading to an increase in the thickness of the reaction layer(2.6−3.1μm)and a decrease in the wetting angle(93.9°−91.0°).The addition of Al_(2)O_(3) and TiO_(2) dopants leads to the formation of Al_(2)TiO_(5) composite oxides in the reaction products,which effectively inhibits the interfacial reaction.The increase in TiO_(2) dopant contents(0−8 wt.%)further promotes the formation of Al_(2)TiO_(5),which decreases the thickness of the interfacial reaction layer(3.9−1.2μm)and increases the wetting angle(95.0°−103.8°).The introduced dopants enhance the packing density of the shell surface,while simultaneously suppress the diffusion of active metal elements from the alloy matrix to the interface.
基金supported by the National Natural Science Foundation of China(No.21571062)the Program for Professor of Special Appointment(Eastern Scholar)at the Shanghai Institutions of Higher Learning to JGL,and the Fundamental Research Funds for the Central Universities(No.222201717003)。
文摘Exploiting non-precious metal catalysts with excellent oxygen reduction reaction(ORR)performance for energy devices is paramount essential for the green and sustainable society development.Herein,low-cost,high-performance biomass-derived ORR catalysts with an asymmetric Fe-N_(3)P configuration was prepared by a simple pyrolysis-etching technique,where carboxymethyl cellulose(CMC)was used as the carbon source,urea and 1,10-phenanthroline iron complex(FePhen)as additives,and Na_(3)PO_(4)as the phosphorus dopant and a pore-forming agent.The CMC-derived FeNPC catalyst displayed a large specific area(BET:1235 m^(2)g^(-1))with atomically dispersed Fe-N_(3)P active sites,which exhibited superior ORR activity and stability in alkaline solution(E_(1/2)=0.90 V vs.RHE)and Zn-air batteries(P_(max)=149 mW cm^(-2))to commercial Pt/C catalyst(E_(1/2)=0.87 V,P_(max)=118 mW cm^(-2))under similar experimental conditions.This work provides a feasible and costeffective route toward highly efficient ORR catalysts and their application to Zn-air batteries for energy conversion.
基金supported by the National Natural Science Foundation of China(Grant Nos.52272103 and 52072010)Beijing Natural Science Foundation(Grant Nos.2242029 and JL23004).
文摘High temperature piezoelectric energy harvester(HTPEH)is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors.However,simultaneously excellent performances,including high figure of merit(FOM),insulation resistivity(ρ)and depolarization temperature(Td)are indispensable but hard to achieve in lead-free piezoceramics,especially operating at 250°C has not been reported before.Herein,well-balanced performances are achieved in BiFeO3–BaTiO3 ceramics via innovative defect engineering with respect to delicate manganese doping.Due to the synergistic effect of enhancing electrostrictive coefficient by polarization configuration optimization,regulating iron ion oxidation state by high valence manganese ion and stabilizing domain orientation by defect dipole,comprehensive excellent electrical performances(Td=340°C,ρ250°C>10^(7)Ωcm and FOM_(250°C)=4905×10^(–15)m^(2)N^(−1))are realized at the solid solubility limit of manganese ions.The HT-PEHs assembled using the rationally designed piezoceramic can allow for fast charging of commercial electrolytic capacitor at 250°C with high energy conversion efficiency(η=11.43%).These characteristics demonstrate that defect engineering tailored BF-BT can satisfy high-end HT-PEHs requirements,paving a new way in developing selfpowered wireless sensors working in HT environments.
基金financially supported by the Taishan Scholars Program of Shandong Province(No.tsqn202103051)the Science and Technology Project of Xinjiang Bingtuan Supported by the Central Government(No.2022BC001)the Project of Scientific Research in Shihezi University(No.CXFZ202205)。
文摘In this paper,low-temperature dielectric-blocked discharge plasma(DBD)was employed for the first time to treat silica-doped H_(4)PMo_(11)VO_(40)(HPAV)catalysts(DBD(Ar/x)-MF-Catal)and apply them in the catalytic methacrolein(MAL)selective oxidation to produce methacrylic acid(MAA).This work investigates in detail the controllable regulation of the concentration of oxidation states on silica-doped HPAV catalysts by adjusting the DBD discharge with controlled changes in voltage,current,treatment time,and treatment medium.It reports the intrinsic correlation between oxidation states and MAL oxidation performance.The research results indicated that the catalytic performance was related to the presence of oxygen vacancies and oxygen species(VO^(2+)),and are the main reason for the selective oxidation of MAL to MAA.Besides,the generation of oxygen vacancies and VO^(2+)altered localized electrons,which resulted in the easier activation of O_(2).Theoretical calculations of DFT also proved the formation mechanism of oxygen vacancies and VO^(2+)and electron properties on high-performance polymers,which elucidated the intrinsic influence of catalyst components.The DBD(Ar/10)-MF-Catal catalysts with suitable VO^(2+)and oxygen vacancy concentrations exhibited the highest catalytic performance with 90%MAL conversion and 70%MAA selectivity and showed good stability(500 h).
基金supported by the Taishan Scholars Program of Shandong Province(tsqn202103051)Tianshan Talents Training Program of Xinjiang(Science and Technology Innovation Team,2022TSYCTD0021)+2 种基金the Science and Technology Project of Xinjiang Bingtuan Supported by Central Government(2022BC001)the project of scientific research in Shihezi University(CXFZ202205)special funds for over provincial level leading talent of Yantai City.
文摘In this study,a catalyst was synthesized using a two-step in-situ molecular beam epitaxy method to grow H_(4)PMo_(11)VO_(40)(HPAV)on amination-treated SiO_(2) nanoparticles,which served as both dopant and host agents.SiO_(2) dopant was modified with(3-aminopropyl)triethoxysilane(APTS),facilitating the formation of ammonium ions that enhanced the overall positive charge.This modification enabled the effective dispersion and exposure of HPAV's active species and induced a structural transformation of HPAV from a triclinic to a cubic crystal phase.The two-step hosting growth process optimized the proportions of Cs^(+),H^(+)and NH_(4)^(+)antinuclear ions,thereby fine-tuning the synergistic catalysis of oxidation and acidity,as well as the oxidative sensitivity at HPAV catalytic interface.The resultant 8(HPAV)&4(Cs_(3)PAV)-NH_(2)-SiO_(2) catalyst achieved a methacrolein(MAL)conversion rate of 84%and a methacrylic acid(MAA)selectivity of 71%.Even after 10.5 h of reaction time,the catalyst retained its high dispersion,cubic crystal structure,and Keggin configuration,demonstrating stable catalytic performance over a continuous 200-h reaction period.
基金supported by the Fundamental Research Program of Shanxi Province(Nos.202303021212159 and 202303021222190)the National Natural Science Foundation of China(No.62222403)+2 种基金the Higher Education Institutions Science and Technology Innovation Program of Shanxi Province(No.2023L160)the Scientific Research Fund of Hunan Provincial Education Department(No.23B0842)the Natural Science Foundation of Shanxi Normal University(Nos.JCYJ2024017 and JCYJ2023015)。
文摘Doping plays a pivotal role in enhancing the performance of organic semiconductors(OSCs)for advanced optoelectronic and thermoelectric applications.In this study,we systematically investigated the doping performance and applicability of the ionic dopant 4-isopropyl-4′-methyldiphenyliodonium tetrakis(penta-fluorophenyl-borate)(DPI-TPFB)as a p-dopant for OSCs.Using the p-type OSC PBBT-2T as a model system,we demonstrated that DPI-TPFB shows significant doping effect,as confirmed by ESR spectra,ultraviolet-visible-near-infrared(UV-vis-NIR)absorption,and work function analysis,and enhances the electronic conductivity of PBBT-2T films by over four orders of magnitude.Furthermore,DPI-TPFB exhibited broad doping applicability,effectively doping various p-type OSCs and even imparting p-type characteristics to the n-type OSC N2200,transforming its intrinsic n-type behavior into p-type.The application of DPI-TPFB-doped PBBT-2T films in organic thermoelectric devices(OTEs)was also explored,achieving a power factor of approximately 10μW·m^(-1)·K^(-2).These findings highlight the potential of DPI-TPFB as a versatile and efficient dopant for integration into organic optoelectronic and thermoelectric devices.
基金financially supported by the National Natural Science Foundation of China (No. 52004164)the Funding Program of Science and Technology Department of Liaoning Province, China (No. 2023-MSLH-249)the Funding Program of Education Department of Liaoning P rovince, China (No. LMGD2023018)。
文摘Fe–Ga sheets with large magnetostriction are required for improving the conversion efficiency under the ultra-high frequencymagnetic field. Trace Tb element doping can simultaneously improve the magnetostriction and ductility of Fe–Ga alloy. However, the im-pact of trace Tb doping on the microstructure and magnetostriction of Fe–Ga thin sheets is an open question. In this paper, the effects oftrace Tb addition on the secondary recrystallization and magnetostriction of Fe–Ga thin sheets are systematically studied by comparing thecharacteristics evolution of precipitation, texture, and nanoinclusions. The results indicate that trace Tb addition accelerates the secondaryrecrystallization of Goss texture due to the combined action of the bimodal size distributed precipitates, smaller grains, and more HEGBsin primary recrystallization. After quenching at 900℃, the magnetostriction value in 0.07 at %Tb-doped Fe_(81)Ga_(19) thin sheets increases by 30% to that of Fe_(81)Ga_(19) thin sheets. The increase in magnetostriction is attributed to the decrease in the number of Tb-rich precipitates andthe higher density of the nanometer-sized modified-D0_(3) inclusions induced by the dissolving of trace Tb elements after quenching. Theseresults demonstrate a simple and efficient approach for preparing Fe–Ga thin sheets with a large magnetostrictive coefficient by a combin-ation of trace RE element addition and conventional rolling method.
基金supported by the National Natural Science Foundation of China(22408061 and 22468005)Program for Introducing High-Level Talents from Guangxi University,and Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology(2023Z014).
文摘Oxygen-rich porous carbons are promising candidates for the carbon-based cathodes of zinc ion hybrid capacitors(ZIHCs).Potassium activation is a traditional and effective way to prepare oxygen-rich porous carbons.Efficient potassium activation is the key to develop high-performance oxygen-rich porous carbon cathodes.Herein,the alkali lignin,extracted from eucalyptus wood by geopolymer-assisted low-alkali pretreatment,is used to prepare oxygen-rich lignin-derived porous carbons(OLPCs)through KOH activation and K_(2)CO_(3)activation at 700-900℃.KOH activation constructs a hierarchical micro-mesoporous structure,while K_(2)CO_(3)activation constructs a microporous structure.Furthermore,K_(2)CO_(3)activation could more efficiently construct active oxygen(C=O)species than KOH activation.The OLPCs prepared by KOH/K_(2)CO_(3)activations at 800℃show the highest microporosity(78.4/87.7%)and C=O content(5.3/8.0 at.%).Due to that C=O and micropore adsorb zinc ions,the OLPCs prepared by K_(2)CO_(3)activation at 800℃with higher C=O content and microporosity deliver superior capacitive performance(256 F g^(-1)at 0.1 A g^(-1))than that by KOH activation at 800℃(224 F g^(-1)at 0.1 A g^(-1)),and excellent cycling stability.This work provides a new insight into the sustainable preparation of oxygenrich porous carbon cathodes through efficient potassium activation for ZIHCs.
基金supported by the National Natural Science Foundation of China(Nos.52001066,21805039,22375045,22373015 and 22271046)the Natural Science Foundation of Fujian Province(No.2023J01500)Young teacher training program of Fujian Normal University(No.SDPY2023013).
文摘Although lots of efforts have been devoted on new less hygroscopic dopants to address problems in hole transport materials(HTM),the long-time post-oxidation and the volatilization of 4-tert-butylpyridine(tBP)are still issues.A new doping mechanism for spiro-OMeTAD by disulfiram(TETD)is revealed in this work.Owing to its disulfide bond,TETD can be activated easily to produce reactive sulfur for the rapid oxidation of spiro-OMeTAD in the absence of oxygen with formation of[spiro-OMeTAD•]+[SC(S)N(C_(2)H_(5))_(2)]^(-).Thus,in this situation,the Li+ion has the opportunity to coordinate tBP and fix each other in HTM film.DFT calculations suggest that the resulting favorable energy(with a△E of−1.29 eV)must come from the mutual interactions among Li^(+),TFSI^(−),and tBP,which is different from the well-known doping process that tBP would not participate in the doping reaction.As a result,the introduction of a new radical into the HTM greatly reduce device performance fluctuations due to the environmental dependence and inhibit tBP volatilizing for enhanced long-term stability.
基金supported by the National Key Research and Development Program of China(2022YFA1505700)National Natural Science Foundation of China(22475214 and 22205232)+2 种基金Talent Plan of Shanghai Branch,Chinese Academy of Sciences(CASSHB-QNPD-2023-020)Natural Science Foundation of Fujian Province(2023J06044)the Self-deployment Project Research Program of Haixi Institutes,Chinese Academy of Sciences(CXZX-2022-JQ06 and CXZX-2022-GH03)。
文摘Aberration-corrected annular dark-field scanning transmission electron microscopy(ADF-STEM)is a powerful tool for structural and chemical analysis of materials.Conventional analyses of ADF-STEM images rely on human labeling,making them labor-intensive and prone to subjective error.Here,we introduce a deep-learning-based workflow combining a pix2pix network for image denoising and either a mathematical algorithm local intensity threshold segmentation(LITS)or another deep learning network UNet for chemical identification.After denoising,the processed images exhibit a five-fold improvement in signal-to-noise ratio and a 20%increase in accuracy of atomic localization.Then,we take atomic-resolution images of Y–Ce dual-atom catalysts(DACs)and Fe-doped ReSe_(2) nanosheets as examples to validate the performance.Pix2pix is applied to identify atomic sites in Y–Ce DACs with a location recall of 0.88 and a location precision of 0.99.LITS is used to further differentiate Y and Ce sites by the intensity of atomic sites.Furthermore,pix2pix and UNet workflow with better automaticity is applied to identification of Fe-doped ReSe_(2) nanosheets.Three types of atomic sites(Re,the substitution of Fe for Re,and the adatom of Fe on Re)are distinguished with the identification recall of more than 0.90 and the precision of higher than 0.93.These results suggest that this strategy facilitates high-quality and automated chemical identification of atomic-resolution images.
基金financially supported by the National Natural Science Foundation of China(Nos.12034002 and 12375283)。
文摘Doping small amounts at the A-site or B-site of SmCrO_(3)ceramics is a promising approach for modifying their microstructure,as well as their magnetic and dielectric properties.In this study,polycrystalline ceramics of Sm_(1-x)Ni_(x)CrO_(3)(x=0,0.05,and 0.20)and SmCr_(1-y)Ni_(y)O_(3)(y=0.05 and 0.20)were synthesized via a conventional solid-state reaction.X-ray diffraction validated that all the doped ceramics maintained an orthorhombic crystalline structure consistent with the Pbnm space group.Furthermore,X-ray photoelectron spectroscopy demonstrated the presence of Ni^(2+)ions in the doped specimens.Notably,doping resulted in significant enhancement of low-temperature magnetic properties,particularly in samples doped at the A-site,such as Sm0.80Ni0.20CrO_(3).Compared with the pristine sample,the maximum magnetization of Sm_(0.8)0Ni_(0.2)0CrO_(3)increased by approximately 60.9%and 93.5%in the zero-field cooling and field-cooling modes,respectively,in an external magnetic field of 100 Oe.Furthermore,the dielectric constants of the Ni-doped ceramics initially exceeded that of the pristine sample as the temperature increased.At equivalent doping ratios,A-site doping demonstrated superior performance over B-site doping,including higher magnetization,lower dielectric loss,and enhanced electrical quality factors.
基金supported by the National Natural Science Foundation of China(52172238,52102304,51902264)Open Project of Shaanxi Laboratory of Aerospace Power(2021SXSYS-01-03)the Fundamental Research Funds for the Central Universities(3102019JC0005)。
文摘Lithium salt-based hole transport layer(HTL)dopants commonly used in perovskite solar cells(PSCs)are known to negatively impact stability due to their intrinsic hygroscopic properties and ion migration.In this study,we introduce an ammonium salt,p-methoxyphenylethylamine bis(trifluoromethyl)sulfoni mide(MPT),as a novel dual-function dopant for the HTL in PSCs.The chemical interaction between MPT and the widely used HTL material spiro-OMeTAD generates high concentrations of spiroOMeTAD^(+)radicals,effectively enhancing the doping of spiro-OMeTAD.Additionally,MPT reacts with the perovskite layer,forming a 2D perovskite structure at the perovskite/HTL interface,which passivates defects and suppresses interfacial ion migration.As a result,PSCs with MPT doping achieved a remarkable power conversion efficiency(PCE)of 25.52%for small-area devices(0.045 cm^(2))and 21.01%for mini-modules(16.8 cm^(2)).Moreover,the incorporation of MPT significantly enhances the moisture,light,and thermal stability of the PSCs by eliminating Li^(+)and suppressing I-migration.Notably,PSCs with MPT-doped PTAA retained 84%of their initial PCE after 1,300 h of aging at 60℃in a nitrogen-filled glovebox.Our work presents a unique doping strategy for the HTL in PSCs,offering a promising approach to simultaneously improve both the stability and efficiency of these devices.
基金supported by the National Natural Science Foundation of China(Nos.12034002 and 12375283).
文摘Doping can optimize the magnetic and dielectric properties of SmCrO_(3),thereby expanding its application of electronic sensing,information storage and low-frequency capacitors.Herein,the ceramic composites of SmCrO_(3),Sm_(1-x)Eu_(x)CrO_(3)(x=0.05 and 0.20)and SmCr_(1-y)Eu_(y)O_(3)(y=0.05 and 0.20)were prepared by traditional solid-state reaction.The pristine and Eu-doped SmCrO_(3)samples were characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM)and transmission electron microscopy(TEM).The characterization results confirm the uniform doping of Eu^(3+)into SmCrO_(3),with all compounds exhibiting an orthorhombic structure and good crystallinity.The temperature-dependent magnetization measurements show that doping does not change the Néel temperature(TN,197 K)and spin reorientation temperature(TSR,34 K)of all the Eu^(3+)doped SmCrO_(3)ceramics.Notably,the magnetization of Sm_(1-x)Eu_(x)CrO_(3)(x=0.05 and 0.20)increases with greater doping content,whereas the magnetization of SmCr_(1-y)Eu_(y)O_(3)(y=0.05,0.20)decreases with increased doping levels.The magnetizations of the Eu^(3+)doped SmCrO_(3)samples can be tuned between 0.54 and 0.79 emu·g^(-1)under 100 K and 20 kOe.The dielectric measurements illustrate that the doped samples exhibit higher dielectric constant and lower dielectric loss than those of pristine SmCrO_(3)at temperatures exceeding 300 K.This work presents a straightforward method for effectively modulating the magnetic and dielectric properties of SmCrO_(3).
基金supported by Research Project for‘Carbon Upcycling Project for Platform Chemicals’of the National Research Foundation(NRF)funded by the Ministry of Science and ICT,Republic of Korea(grant number:2022M3J3A1050053)supported by the National Research Council of Science&Technology(NST)grant by the Korean government(MSIT)(No.CAP21011-100)+1 种基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(RS-2023-00302697)institutional program grants from the Korea Institute of Science and Technology。
文摘To develop an efficient electrochemical CO_(2)reduction reaction(CO_(2)RR)for the production of C_(2)chemicals,improvements in the Cu catalyst are necessary.Doping is widely used for catalyst enhancement;however,only a few elements have been examined.This study proposes guidelines for the selection of Cu catalyst dopants to promote ethylene production.It was hypothesized that the dopant chemical state highly influences the CO_(2)RR catalytic activity.In the case of dopants possessing a standard reduction potential within the CO_(2)RR potential region(e.g.,Mn and Ni),low Faradaic efficiency(FE)toward ethylene production was obtained owing to the presence of a metallic dopant(10.7%for Ni dopant).In contrast,a low standard reduction potential led to a stable high oxidation state for the dopant,yielding abundant Cu^(δ+)species with modified electronic structures and enhancing the CO_(2)RR catalytic activity for ethylene production(42.1%for Hf dopant).We expected that a dopant with a low standard reduction potential is difficult to reduce,which leads to a stable Cu-O-X bond and induces a stable Cu^(δ+)species.Our study provides insights into how to select dopant for various catalyst to enhance CO_(2)RR catalytic activity.
基金supported by the National Natural Science Foundation of China(Grant No.22275210)the Natural Science Foundation of Shandong Province(Grant No.ZR2024QB025,ZR2023ME155)the Taishan Scholar Project of Shandong Province(tsqn202306226)。
文摘Optimizing the energy barrier of 2H-to-1T phase transformation plays a crucial role in modulating the intrinsic electronic structure of MoS_(2)to achieve satisfactory water-splitting performance,but remains a significant challenge.Herein,we report a vacancy occupation-triggered phase transition strategy to fabricate a core-shell 1T phase nanorod structure,which is composed of S-vacancies decorated MoS_(2)as the core,and N,P co-doped carbons as the shell(1T-MoS_(2)@NPC).The co-insertion of N and P dopants into MoS_(2)can occupy partial S-vacancies,triggering a phase transformation from the semiconducting 2H phase to the conducting 1T phase with a reduced energy barrier.Profiting from the strong coupling effect between N,P dopants and S-vacancies,the as-made 1T-MoS_(2)@NPC exhibits excellent electrocatalytic activity for both HER(η_(10)=148 m V)and OER(η_(10)=232 mV)in alkaline solution.Meanwhile,a low cell voltage of 1.62 V is needed to drive a current density of 10mA cm^(-2)in 1.0 M KOH electrolyte.The theoretical calculation results reveal that the S-vacancies decorated C atoms in the meta-position relative to N,P atoms represent the most active HER and OER sites,which synergistically upshift the d band center and balance the rate-determining step,thus ensuring the simultaneous optimization of adsorption free energy and electronic structure.This vacancy-occupation-derived phase transformation strategy caused by non-metallic doping may provide valuable guidance for enhancing the performance of alkaline water electrolysis.
基金financially supported by the National Key Re-search and Development Program of China(No.2022YFC3700801)the Key R&D Program of Shandong Province,China(No.2024SFGC0102),the Jinan Bureau of Education(No.JNSX2023015)the Jinan Bureau of Science and Technology(No.202333042).
文摘Tetravalent tin(Sn^(4+))-based inorganic perovskite semiconductors like Cs_(2)SnI_(6)are expected to replace lead-based perovskite counterparts due to advantages such as structural stability and environmental friendliness.In this paper,we reported the dopant compensation effect in the component-dependent self-doped(111)-oriented Cs_(2)SnI_(6)thin films grown with pulsed laser deposition(PLD)at room temperature.The films were grown on(100)-SrTiO_(3)(STO)substrates at room temperature by PLD.Hall results of the Cs_(2)SnI_(6)films with different components realizing by controlling the ratio of SnI_(4)/CsI in the targets demonstrate a clear change of conductivity type from N-type to P-type,while the carrier concentration decreases from 1018 to 1013 and accordingly the film resistivity increases significantly from 3.8 to 2506Ωcm.The defect-relatedopticalfingerprints of Cs_(2)SnI_(6)films werealsoinvestigated withtemperature-dependent photoluminescence spectroscopy.At low temperatures of 10 K,the Cs_(2)SnI_(6)films exhibit donor-bound(D^(0)X)and donor-acceptor pair(DAP)emission,respectively,due to the self-doping effect.These re-sults indicate that controlling the composition of the PLD target is a powerful way to tune the electrical properties of Cs_(2)SnI_(6)films for possible applications in solar cells or X-ray detectors.
基金supported by the Open Research Fund of Songshan Lake Materials Laboratory(No.2021SLABFK09)the National Natural Science Foundation of China(No.22109093)+1 种基金the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning and the Shanghai Rising-Star Program(No.19QA1403800)the Project of Innovative Development Agency of Republic of Uzbekistan(No.FZ-20200929177)and Shanghai Technical Service Computing Center of Science and Engineering,Shanghai University.
文摘Inverted perovskite solar cells(PSCs)have stood out in recent years for their great potential in offering low-temperature compatibility,long-term stability and tandem cell suitability.However,challenges persist,particularly concerning the use of nickel oxide nanoparticles(NiO_(x)NPs)as the hole transport material,where issues such as low conductivity,impurity-induced aggregation and interface redox reactions significantly hinder device performance.In response,this study presents a novel synthesis method for NiO_(x)NPs,leveraging the introduction of ammonium salt dopants(NH_(4)Cl and NH_(4)SCN),and the solar cell utilizing the doped NiO_(x)substrate exhibits much enhanced device performance.Furthermore,doped solar cells reach 23.27%power conversion efficiency(PCE)when a self-assembled monolayer(SAM)is further employed.This study provides critical insights into the synthesis and growth pathways of NiO_(x)NPs,propelling the development of efficient hole transport materials for high-performance PSCs.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Science(Grant Nos.XDA25050200 and XDA25010100)the National Natural Science Foundation of China(Grant Nos.12175309,12475252,and 12275356)+2 种基金the Defense Industrial Technology Development Program(Grant No.JCKYS2023212807)the Natural Science Foundation of Hunan Province,China(Grant No.2025JJ20007)the Postgraduate Scientific Research Innovation Project of Hunan Province,China(Grant No.CX20230005).
文摘In the direct drive inertial confinement fusion(ICF)scheme,a rippled interface between the ablator and the deuterium–tritium ice fuel can feed out and form perturbation seeds for the ablative Rayleigh–Taylor instability,with undesirable effects.However,the evolution of this instability remains insufficiently studied,and the effects of high-Z dopant on this instability remain unclear.In this paper,we develop a theoretical model to calculate the feedout seeds and describe this instability.Our theory suggests that the feedout seeds are determined by the ablation pressure and the adiabatic index,while the subsequent growth depends mainly on the ablation velocity.Two-dimensional radiation hydrodynamic simulations confirm our theory.It is shown that targets with high-Z dopant in the outer ablator exhibit more severe feedout seeds,because of their higher ionization compared with undoped targets.The X-ray pre-ablation in high-Z doped targets significantly suppresses subsequent growth,leading to suppression of short-wavelength perturbations.However,for long-wavelength perturbations,this suppression is weakened,resulting in increased instability in high-Z doped targets.The results are helpful for understanding the innerinterface-initiated instability and the influence of high-Z dopant on it,providing valuable insights for target design and instability control in ICF.
文摘Nanoscale Sb doped titanium dioxide thin films photocatalyst （Ti1-xSbO2） were obtained from dip-coating sol-gel method. The influence of dopant Sb density on the crystal structure and the phase transformation of the thin tilms were characterized by X-ray diffraction （XRD） and Raman spectra. The results of XRD showed that as prepared lilms were not only in anatase state but also in brookite. The crystalline size was estimated to be around 13.3-20 nm. Raman spectra indicated there coexisted other phases and a transformation from brookite to anatase in the samples doped with 0.2% Sb. After doping a proper amount of Sb, the cryst,allization rate and the content of the anatase Ti1-x, SbO2 in the thin films was clearly enhanced because Sb replaced part. of the Ti of TiO2 in the thin films. The anode current density （photocurrent density） and the first order reaction speed constant （k） of t.hin films doped with 0.2% Sb reached 42.49 μA/cm^2 and 0.171 h/cm^2 under 254 nm UV illumination, respectively, which is about 11 times and 2 times that of the non doped TiO2 anode prepared by the same method respectively.
文摘The crystal of high concentration Nd:YAG was grown by flux method and diode pu mp microcavity laser was studied.High efficiency and frequency solid state lase r was built on research and development.some applications such as target designa tion,laser radar,rangefinder,CATV etc. In order to maximize pump efficiency and power output,the Nd concentration shoul d be made as high as possible without degrading the gain through concentration q uenching.In crystal grown by Czochraski method.it is difficult to increase the N d concentration over 1.2% because of Nd segregation in the melt (yttrium aluminum garnet),which leads to large nonuniformities in doping.However,by using the f lux met hod growth technique,it is possible to grow uniformly doped crystal as much as 4 % Nd concentration YAG.
