The development of cost-effective,highly efficient and stable catalysts is critical to promote the industrial alkaline hydrogen evolution reaction(HER).However,single-component catalysts often cannot handle the multip...The development of cost-effective,highly efficient and stable catalysts is critical to promote the industrial alkaline hydrogen evolution reaction(HER).However,single-component catalysts often cannot handle the multiple kinetic steps during hydrogen production.To address this challenge,a heterogeneous catalyst comprising metal Co,CoO and carbon-doped Mo_(2)N(Co–CoO–C/Mo_(2)N/CC)was synthesized by heat treatment of carbon cloth-supported CoMoO_(4) microrods in a mixed reduction atmosphere.The resulting catalyst has rich interfaces,exhibiting excellent initial HER activity with an overpotential of 27 mV at 10 mA·cm^(−2) and a Tafel slope of 37 mV·dec^(−1).Further studies show that the activity and stability of the catalyst can be tailored by the dynamic surface reconfiguration and doping effects.The carbon doping and high crystallinity in Mo_(2)N help to reduce the dissolution of Mo and the surface metal Co is preferentially converted into stable Co(OH)2,thus stabilizing the structure of the catalyst and coordinating various reaction kinetics.In an electrolyzer comprising a heterogeneous Co–CoO–C/Mo_(2)N cathode and NiFe layered double hydroxides(LDH)anode,only 1.58 V is required to achieve a current density of 50 mA·cm^(−2),outperforming Pt/RuO catalysts.After continuous electrolysis for 100 h,the potential increases by merely 19 mV from the initial 1.58 V,indicating excellent stability.This study presents a novel strategy for developing highly active and stable heterogeneous catalysts,offering insights into the dynamic evolution of catalyst structures and laying the groundwork for designing efficient and stable composite catalysts for energy conversion applications.展开更多
The limited ion/electron transport kinetics and insufficient crystalline stability of TiNb_(2)O_(7)(TNO)present significant challenges to the development of high-performance lithium-ion batteries(LIBs)with fastchargin...The limited ion/electron transport kinetics and insufficient crystalline stability of TiNb_(2)O_(7)(TNO)present significant challenges to the development of high-performance lithium-ion batteries(LIBs)with fastcharging capabilities and long cycle life.Here we propose a dual-modification strategy combining Ndoped carbon(NC)coating and Co^(2+)/W^(6+)doping,which not only enhances ionic and electronic conductivity but also effectively regulates volume expansion during electrochemical cycling.Upon Li+ion insertion,a significant reduction in the unit cell expansion coefficient of doped TNO is observed,from 7.48%(pristine TNO)to 5.37%(with 3%W^(6+)doping)and 4.65%(with 3%Co^(2+)doping),alo ng with lowered lattice distortion and improved uniformity in internal strain release.Density functional theory(DFT)simulation demonstrates that Co^(2+)and W^(6+)ions preferentially substitute Ti^(4+)sites in the TNO crystal,leading to the improved electronic conductivity by narrowing the bandgap.Moreover,Co^(2+)doping creates lower electron density and wider Li+ion transport channels than W^(6+)doping.The optimized 3Co-TNO@NC anode delivers a remarkable power density of 11.0 kW kg^(-1)at 20 C while maintaining a high reversible capacity of 150.9 mAh g^(-1)at 10 C after 2000 cycles.It also exhibits excellent compatibility in full cells,paired well with LiFePO_(4)(137.9 mAh g^(-1)after 2000 cycles)and Ni-rich LiNi_(0.8)Co_(0.1)Mn_(0.1)(130.9 mAh g^(-1)after 500cycles)cathodes at 5 C,highlighting its potential as a high-safety,low-strain anode material for highpower LIBs.展开更多
To achieve high efficiency of water electrolysis to produce hydrogen(H_(2)),developing non-noble metal-based catalysts with consid-erable performance have been considered as a crucial strategy,which is correlated with...To achieve high efficiency of water electrolysis to produce hydrogen(H_(2)),developing non-noble metal-based catalysts with consid-erable performance have been considered as a crucial strategy,which is correlated with both the interphase properties and multi-metal synergistic effects.Herein,as a proof of concept,a delicate NiCo(OH)_(x)-CoyW catalyst with a bush-like heterostructure was realized via gas-template-assisted electrodeposition,followed by an electrochemical etching-growth process,which ensured a high active area and fast gas release kinetics for a superior hydrogen evolution reaction,with an overpotential of 21 and 139 mV at 10 and 500 mA cm^(−2),respectively.Physical and electrochemical analyses demonstrated that the synergistic effect of the NiCo(OH)_(x)-Co_(y)W heteroge-neous interface resulted in favorable electron redistribution and faster electron transfer efficiency.The amorphous NiCo(OH)_(x) strengthened the water dissociation step,and metal phase of CoW provided sufficient sites for moderate H immediate adsorption/H_(2) desorption.In addition,NiCo(OH)_(x)-CoyW exhibited desirable urea oxidation reaction activity for matching H_(2) generation with a low voltage of 1.51 V at 50 mA cm^(−2).More importantly,the synthesis and testing of the NiCo(OH)_(x)-CoyW catalyst in this study were all solar-powered,sug-gesting a promising environmentally friendly process for practical applications.展开更多
Up to now, perovskite solar cells(PSCs) have reached a certified 25.5% efficiency. As a promising photo-electric material, the metal halide perovskite possesses many outstanding properties such as tunable bandgap, lon...Up to now, perovskite solar cells(PSCs) have reached a certified 25.5% efficiency. As a promising photo-electric material, the metal halide perovskite possesses many outstanding properties such as tunable bandgap, long diffusion length, high absorption coefficient and carrier mobility. In spite of these remarkable properties, defects are inevitable during the solution processing. Therefore, many efforts have been made to reduce defects in perovskite films and thus improve the performance of devices. Among them,substitution or doping engineering is one of the most studied methods. Meanwhile, due to the poor stability of the organic-inorganic hybrid perovskite and the toxicity of Pb-based perovskite materials, all inorganic perovskite and lead-less or lead-free perovskite have emerged as promising materials. Here,we focus on the defect engineering especially substitutions on different sites in an ABX_(3) structure. The particular attention is devoted towards lead-less or lead-free perovskites, and we discuss several common elements or groups used to partially replace Pb^(2+). It is noted that proper elemental doping at different sites is an important guarantee for obtaining high-performance lead-less or lead-free PSCs.展开更多
Lithium-aluminum layered double hydroxides(LiAl-LDH)have been be successfully applied in commercial-scale for lithium extraction from salt lake brine,however,further advancement of their applications is hampered by su...Lithium-aluminum layered double hydroxides(LiAl-LDH)have been be successfully applied in commercial-scale for lithium extraction from salt lake brine,however,further advancement of their applications is hampered by suboptimal Li^(+)adsorption performance and ambiguous extraction process.Herein,a doping engineering strategy was developed to fabricate novel Zn^(2+)-doped LiAl-LDH(LiZnAl-LDH)with remarkable higher Li^(+)adsorption capacity(13.4 mg/g)and selectivity(separation factors of 213,834,171 for Li^(+)/K^(+),Li^(+)/Na^(+),Li^(+)/Mg^(2+),respectively),as well as lossless reusability in Luobupo brine compared to the pristine LiAl-LDH.Further,combining experiments and simulation calculations,it was revealed that the specific surface area,hydrophilic,and surface attraction for Li^(+)of LiZnAl-LDH were significantly improved,reducing the adsorption energy(Ead)and Gibbs free energy(ΔG),thus facilitating the transfer of Li^(+)from brine into interface followed by insertion into voids.Importantly,the intrinsic oxygen vacancies derived from Zn-doping depressed the diffusion energy barrier of Li^(+),which accelerated the diffusion process of Li^(+)in the internal bulk of LiZnAl-LDH.This work provides a general strategy to overcome the existing limitations of Li^(+)recovery and deepens the understanding of Li^(+)extraction on LiAl-LDH.展开更多
Cadmium telluride(CdTe)thin film solar cells have gained significant attention in the photovoltaic industry due to their high efficiency and low cost.CdTe solar cells have achieved a high-power conversion efficiency o...Cadmium telluride(CdTe)thin film solar cells have gained significant attention in the photovoltaic industry due to their high efficiency and low cost.CdTe solar cells have achieved a high-power conversion efficiency of 23.1%.To further boost the device's performance,it is crucial to systematically tune the doping concen-tration and carrier concentration,which are dominated by the doping approach and the following dopant activation processes.Both Group I elements(e.g.,Cu)and Group V elements(e.g.,As)doping have demonstrated high efficiency and utilizing various doping techniques.This review provides an overview of the history of the CdTe thin film technology,doping mechanisms,doping techniques,challenges,and potential solutions to further improve device performance.展开更多
To address the challenge of insufficient oxygen vacancies in proton-conducting solid oxide fuel cells(H-SOFC),transition metal elements were doped into the B site of lanthanum ferrite perovskite(ABO3)to enhance its ca...To address the challenge of insufficient oxygen vacancies in proton-conducting solid oxide fuel cells(H-SOFC),transition metal elements were doped into the B site of lanthanum ferrite perovskite(ABO3)to enhance its catalytic activity further.The Mo-doped La_(0.6)Sr_(0.4)Fe_(0.9)Ni_(0.1)O_(3-δ)(LSFNMx,x=0.05,0.1)powder was synthesized via the sol−gel method,and its crystal structure,conductivity,defect chemistry,and electrochemical performance as an H-SOFC cathode were investigated.The prepared material exhibited a hexagonal structure with the R-3c space group and demonstrates good chemical stability under simulated working conditions.Mo doping increased the surface concentration of oxygen vacancies,leading to the accelerated oxygen transportation.Consequently,the polarization resistance(Rpol)and activation energy(Ea)are reduced.Specifically,LSFNM0.05 showed the lowest polarization resistance(approximately 0.26Ω·cm^(2))at 700°C.LSFNM0.05 achieved a maximum power density of 484 mW/cm^(2)at this temperature,outperforming those of LSFN(353 mW/cm^(2))and LSFNM0.1(365 mW/cm^(2)).展开更多
The superior ability of perovskite-type SrNbO_(2) N to absorb intensive visible light makes it a potential semiconductor to produce hydrogen and oxygen by photoelectrochemical(PEC)water splitting under sunlight.The su...The superior ability of perovskite-type SrNbO_(2) N to absorb intensive visible light makes it a potential semiconductor to produce hydrogen and oxygen by photoelectrochemical(PEC)water splitting under sunlight.The surface morphologies,such as shape and structure,of the oxynitride strongly affect its photoactivity,although the mechanism has been hardly studied.Herein,we report a two-dimensional(2D)porous SrNbO_(2) N plate with Zr doping,nitrided from layered perovskite Sr_(5)Nb_(4)O_(15) and also its largely enhanced PEC water splitting activity.Zr^(4+)was doped in Sr_(5)Nb_(4)O_(15) during flux-assisted calcination using KCl,producing 2D-type truncated-octahedral Sr_(5)Nb_(4)O_(15):Zr plates approximately 50 nm in thickness.The nitridation completely transformed Sr_(5)Nb_(4)O_(15):Zr to 2D single-crystalline SrNbO_(2) N:Zr with a large surface area,which was subsequently used to fabricate a thin and uniform photoanode by the spin coating method.As a result,the Co(OH)_(x)/SrNbO_(2) N:Zr/FTO photoanode capable of absorbing visible light of up to 680 nm exhibited an activity of 2.0 mA cm^(-2) at 1.23 V vs the reversible hydrogen electrode for water splitting under AM 1.5G simulated sunlight.This improvement in photoactivity mainly originated from the 2D surface morphology of SrNbO_(2) N:Zr,which is clearly distinguishable from 3D-type oxynitrides.According to electrochemical analyses,the 2D structure of SrNbO_(2) N:Zr boosted the separation and accelerated the transfer of charges photogenerated during the water splitting,thus driving the reaction further.Therefore,the result empirically demonstrates that controlling the surface morphology of SrNbO_(2) N is an effective strategy to suppress the recombination of charges and minimize their diffusion pathway,eventually enhancing the PEC activity.展开更多
The interfacial electric field(IEF) determines the charge carriers transport and the reactivity of heterostructure photocatalyts.Nonetheless, the restricted IEF lead to inefficient interfacial charge transport and ori...The interfacial electric field(IEF) determines the charge carriers transport and the reactivity of heterostructure photocatalyts.Nonetheless, the restricted IEF lead to inefficient interfacial charge transport and oriented accumulation, resulting in low photocatalytic efficiency. Herein, a interfacial chemical-bonded Ti-Bi OBr/1T-Mo S_(1.85)Ohm junction is fabricated via electrostatic self-assembly strategy, in which Ti doping precisely regulates the local electrical structure and work function of Bi OBr,thus boosting the IEF to efficiently drive charge transfer and oriented accumulation to active sites. The femtosecond transient absorption spectroscopy verified that the Ti_(0.1)Bi_(0.9)OBr/1T-Mo S_(1.85)-6% increased the shallow electron trapping(τ_(1)= 0.57 ps)while the depressed recombination of photoinduced electrons with trapped holes(τ_(2)= 71.88 ps) compared to the Bi OBr/1TMo S_(1.85)-6%(τ_(1)= 0.78 ps, τ_(2)= 54.61 ps). More Importantly, the interfacial charge carriers transfer from Ti_(0.1)Bi_(0.9)OBr to 1TMoS_(1.85)(τ_(3)= 86.53 ps) was significantly accelerated by the reinforced IEF compared to Bi OBr/1T-MoS_(1.85)-6%(τ_(3)= 221.51 ps).The N_(2)-to-NH3conversion rate of Ti_(0.1)Bi_(0.9)OBr/1T-Mo S_(1.85)-6% Ohm junction(36.8 μmol g_(cat)^(-1)h^(-1)) was 1.9 and 6.9-fold higher than that of Bi OBr/1T-Mo S_(1.85)-6% and 1T-Mo S_(1.85), respectively. This work provides a new insight into the design of Ohm junction with reinforced IEF for efficient interfacial charge carrier transfer and oriented accumulation towards efficient N_(2)fixation.展开更多
SnSe has received significant attention due to its exceptional optoelectronic and thermoelectric properties,making it a promising candidate for energy conversion applications.To exploit its potential for photo-thermoe...SnSe has received significant attention due to its exceptional optoelectronic and thermoelectric properties,making it a promising candidate for energy conversion applications.To exploit its potential for photo-thermoelectric applications,it is essential to prepare high-quality SnSe single-crystal films and investigate their intrinsic properties and local structure.In this work,pure and Na,Cu doped SnSe films were prepared via pulsed laser deposition(PLD).Orthorhombic SnSe films were successfully deposited along the[100]direction on SrTiO_(3)substrates.Our results show that the growth mode of SnSe films transitions from island-by-layer to 3D island growth as the film thickness increases.Notably,SnSe doped with Na and Cu restores a flatter surface even at larger thicknesses,and the current output of the Na and Cu doped SnSe film under optical and thermal excitations exhibited a significant improvement compared to the individual photo-induced and thermal-induced,as well as the sum of both,highlighting its potential for integrated photoelectric-thermoelectric applications.展开更多
In recent decade, Au nanoclusters of atomic precision （AunLm, where L= organic ligand： thiolate andphosphine） have been shown as a new promising nanogold catalyst. The well-defined AunLm catalystspossess unique ele...In recent decade, Au nanoclusters of atomic precision （AunLm, where L= organic ligand： thiolate andphosphine） have been shown as a new promising nanogold catalyst. The well-defined AunLm catalystspossess unique electronic properties and frameworks, providing an excellent opportunity to correlate theintrinsic catalytic behavior with the cluster＇s framework as well as to study the catalytic mechanismsover gold nanoclusters. In this review, we only demonstrate the important roles of the gold nanoclustersin the oxygen activation （e.g., 302 to 102） and their selective oxidations in the presence of oxygen （e.g., COto C02, sulfides to sulfoxides, alcohol to aldehyde, styrene to styrene epoxide, amines to imines, andglucose to gluconic acid）. The size-specificity （Au25 （1.3 nm）, Au38 （].5 nm）, Au144 （1.9 nm）, etc.）, ligandengineering （e.g., aromatic vs aliphatic）, and doping effects （e.g., copper, silver, palladium, and platinum）are discussed in details. Finally, the proposed reactions＇ mechanism and the relationships of clusters＇structure and activity at the atomic level also are presented.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22379116,U2003130 and U2004210)the Outstanding Youth Foundation of Natural Science Foundation of Hubei Province(No.2020CFA099)+1 种基金the Foundation of Science Research Program from Hubei Provincial Department of Education(No.Q20221101)the Innovation group of Key Research and Development Program of Hubei Province(Nos.2021BAA208 and 2022BCA061).
文摘The development of cost-effective,highly efficient and stable catalysts is critical to promote the industrial alkaline hydrogen evolution reaction(HER).However,single-component catalysts often cannot handle the multiple kinetic steps during hydrogen production.To address this challenge,a heterogeneous catalyst comprising metal Co,CoO and carbon-doped Mo_(2)N(Co–CoO–C/Mo_(2)N/CC)was synthesized by heat treatment of carbon cloth-supported CoMoO_(4) microrods in a mixed reduction atmosphere.The resulting catalyst has rich interfaces,exhibiting excellent initial HER activity with an overpotential of 27 mV at 10 mA·cm^(−2) and a Tafel slope of 37 mV·dec^(−1).Further studies show that the activity and stability of the catalyst can be tailored by the dynamic surface reconfiguration and doping effects.The carbon doping and high crystallinity in Mo_(2)N help to reduce the dissolution of Mo and the surface metal Co is preferentially converted into stable Co(OH)2,thus stabilizing the structure of the catalyst and coordinating various reaction kinetics.In an electrolyzer comprising a heterogeneous Co–CoO–C/Mo_(2)N cathode and NiFe layered double hydroxides(LDH)anode,only 1.58 V is required to achieve a current density of 50 mA·cm^(−2),outperforming Pt/RuO catalysts.After continuous electrolysis for 100 h,the potential increases by merely 19 mV from the initial 1.58 V,indicating excellent stability.This study presents a novel strategy for developing highly active and stable heterogeneous catalysts,offering insights into the dynamic evolution of catalyst structures and laying the groundwork for designing efficient and stable composite catalysts for energy conversion applications.
基金support from the BRICS STI Framework Programme(No.52261145703)National Research Foundation+2 种基金Singapore under Award No.NRF-CRP24-2020-0002the Italy-Singapore Science and Technology Cooperation(Grant No.R23101R040)the use of computing resources at the A*STAR Computational Centre and National Supercomputer Centre,Singapore。
文摘The limited ion/electron transport kinetics and insufficient crystalline stability of TiNb_(2)O_(7)(TNO)present significant challenges to the development of high-performance lithium-ion batteries(LIBs)with fastcharging capabilities and long cycle life.Here we propose a dual-modification strategy combining Ndoped carbon(NC)coating and Co^(2+)/W^(6+)doping,which not only enhances ionic and electronic conductivity but also effectively regulates volume expansion during electrochemical cycling.Upon Li+ion insertion,a significant reduction in the unit cell expansion coefficient of doped TNO is observed,from 7.48%(pristine TNO)to 5.37%(with 3%W^(6+)doping)and 4.65%(with 3%Co^(2+)doping),alo ng with lowered lattice distortion and improved uniformity in internal strain release.Density functional theory(DFT)simulation demonstrates that Co^(2+)and W^(6+)ions preferentially substitute Ti^(4+)sites in the TNO crystal,leading to the improved electronic conductivity by narrowing the bandgap.Moreover,Co^(2+)doping creates lower electron density and wider Li+ion transport channels than W^(6+)doping.The optimized 3Co-TNO@NC anode delivers a remarkable power density of 11.0 kW kg^(-1)at 20 C while maintaining a high reversible capacity of 150.9 mAh g^(-1)at 10 C after 2000 cycles.It also exhibits excellent compatibility in full cells,paired well with LiFePO_(4)(137.9 mAh g^(-1)after 2000 cycles)and Ni-rich LiNi_(0.8)Co_(0.1)Mn_(0.1)(130.9 mAh g^(-1)after 500cycles)cathodes at 5 C,highlighting its potential as a high-safety,low-strain anode material for highpower LIBs.
基金This work was financially supported by the National Natural Science Foundations of China(21878061).
文摘To achieve high efficiency of water electrolysis to produce hydrogen(H_(2)),developing non-noble metal-based catalysts with consid-erable performance have been considered as a crucial strategy,which is correlated with both the interphase properties and multi-metal synergistic effects.Herein,as a proof of concept,a delicate NiCo(OH)_(x)-CoyW catalyst with a bush-like heterostructure was realized via gas-template-assisted electrodeposition,followed by an electrochemical etching-growth process,which ensured a high active area and fast gas release kinetics for a superior hydrogen evolution reaction,with an overpotential of 21 and 139 mV at 10 and 500 mA cm^(−2),respectively.Physical and electrochemical analyses demonstrated that the synergistic effect of the NiCo(OH)_(x)-Co_(y)W heteroge-neous interface resulted in favorable electron redistribution and faster electron transfer efficiency.The amorphous NiCo(OH)_(x) strengthened the water dissociation step,and metal phase of CoW provided sufficient sites for moderate H immediate adsorption/H_(2) desorption.In addition,NiCo(OH)_(x)-CoyW exhibited desirable urea oxidation reaction activity for matching H_(2) generation with a low voltage of 1.51 V at 50 mA cm^(−2).More importantly,the synthesis and testing of the NiCo(OH)_(x)-CoyW catalyst in this study were all solar-powered,sug-gesting a promising environmentally friendly process for practical applications.
基金financially supported by the National Key Research and Development Program of China (Grant No.2018YFB2202900)the National Natural Science Foundation of China (Grant Nos. 52192610, 61704131)+3 种基金the Key Research and Development Program of Shaanxi Province (Grant No. 2020GY-310)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University (Grant No. 2020GXLH-Z-018)the Fundamental Research Funds for the Central Universitiesthe Innovation Fund of Xidian University。
文摘Up to now, perovskite solar cells(PSCs) have reached a certified 25.5% efficiency. As a promising photo-electric material, the metal halide perovskite possesses many outstanding properties such as tunable bandgap, long diffusion length, high absorption coefficient and carrier mobility. In spite of these remarkable properties, defects are inevitable during the solution processing. Therefore, many efforts have been made to reduce defects in perovskite films and thus improve the performance of devices. Among them,substitution or doping engineering is one of the most studied methods. Meanwhile, due to the poor stability of the organic-inorganic hybrid perovskite and the toxicity of Pb-based perovskite materials, all inorganic perovskite and lead-less or lead-free perovskite have emerged as promising materials. Here,we focus on the defect engineering especially substitutions on different sites in an ABX_(3) structure. The particular attention is devoted towards lead-less or lead-free perovskites, and we discuss several common elements or groups used to partially replace Pb^(2+). It is noted that proper elemental doping at different sites is an important guarantee for obtaining high-performance lead-less or lead-free PSCs.
基金supports for this work from National Key R&D Program of China(No.2022YFC2906300)the National Natural Science Foundation of China(No.52204283)+2 种基金the Natural Science Foundation of Hubei Province of China(No.2021CFB554)the Key Project of the Science and Technology Research of Hubei Provincial Department of Education(No.D20221605)the CONACYT through the project A1-S-8817.L.J.Z.would like to thank CONACYT for the scholarship for granting his the scholarship No.847199 during his Ph.D study.
文摘Lithium-aluminum layered double hydroxides(LiAl-LDH)have been be successfully applied in commercial-scale for lithium extraction from salt lake brine,however,further advancement of their applications is hampered by suboptimal Li^(+)adsorption performance and ambiguous extraction process.Herein,a doping engineering strategy was developed to fabricate novel Zn^(2+)-doped LiAl-LDH(LiZnAl-LDH)with remarkable higher Li^(+)adsorption capacity(13.4 mg/g)and selectivity(separation factors of 213,834,171 for Li^(+)/K^(+),Li^(+)/Na^(+),Li^(+)/Mg^(2+),respectively),as well as lossless reusability in Luobupo brine compared to the pristine LiAl-LDH.Further,combining experiments and simulation calculations,it was revealed that the specific surface area,hydrophilic,and surface attraction for Li^(+)of LiZnAl-LDH were significantly improved,reducing the adsorption energy(Ead)and Gibbs free energy(ΔG),thus facilitating the transfer of Li^(+)from brine into interface followed by insertion into voids.Importantly,the intrinsic oxygen vacancies derived from Zn-doping depressed the diffusion energy barrier of Li^(+),which accelerated the diffusion process of Li^(+)in the internal bulk of LiZnAl-LDH.This work provides a general strategy to overcome the existing limitations of Li^(+)recovery and deepens the understanding of Li^(+)extraction on LiAl-LDH.
基金supported by the National Science Foundation under contract No.ECCS-2413632,MOMS-2330728,TI-2329871,DMR-2330738,CMMI-2226918,and DMREF-2323766。
文摘Cadmium telluride(CdTe)thin film solar cells have gained significant attention in the photovoltaic industry due to their high efficiency and low cost.CdTe solar cells have achieved a high-power conversion efficiency of 23.1%.To further boost the device's performance,it is crucial to systematically tune the doping concen-tration and carrier concentration,which are dominated by the doping approach and the following dopant activation processes.Both Group I elements(e.g.,Cu)and Group V elements(e.g.,As)doping have demonstrated high efficiency and utilizing various doping techniques.This review provides an overview of the history of the CdTe thin film technology,doping mechanisms,doping techniques,challenges,and potential solutions to further improve device performance.
基金financial support from the National Natural Science Foundation of China(Nos.51922003,52274406)the Fundamental Research Funds for the Central Universities,China(No.FRF-BD-23-02)。
文摘To address the challenge of insufficient oxygen vacancies in proton-conducting solid oxide fuel cells(H-SOFC),transition metal elements were doped into the B site of lanthanum ferrite perovskite(ABO3)to enhance its catalytic activity further.The Mo-doped La_(0.6)Sr_(0.4)Fe_(0.9)Ni_(0.1)O_(3-δ)(LSFNMx,x=0.05,0.1)powder was synthesized via the sol−gel method,and its crystal structure,conductivity,defect chemistry,and electrochemical performance as an H-SOFC cathode were investigated.The prepared material exhibited a hexagonal structure with the R-3c space group and demonstrates good chemical stability under simulated working conditions.Mo doping increased the surface concentration of oxygen vacancies,leading to the accelerated oxygen transportation.Consequently,the polarization resistance(Rpol)and activation energy(Ea)are reduced.Specifically,LSFNM0.05 showed the lowest polarization resistance(approximately 0.26Ω·cm^(2))at 700°C.LSFNM0.05 achieved a maximum power density of 484 mW/cm^(2)at this temperature,outperforming those of LSFN(353 mW/cm^(2))and LSFNM0.1(365 mW/cm^(2)).
基金financially supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.2020R1C1C1006373).
文摘The superior ability of perovskite-type SrNbO_(2) N to absorb intensive visible light makes it a potential semiconductor to produce hydrogen and oxygen by photoelectrochemical(PEC)water splitting under sunlight.The surface morphologies,such as shape and structure,of the oxynitride strongly affect its photoactivity,although the mechanism has been hardly studied.Herein,we report a two-dimensional(2D)porous SrNbO_(2) N plate with Zr doping,nitrided from layered perovskite Sr_(5)Nb_(4)O_(15) and also its largely enhanced PEC water splitting activity.Zr^(4+)was doped in Sr_(5)Nb_(4)O_(15) during flux-assisted calcination using KCl,producing 2D-type truncated-octahedral Sr_(5)Nb_(4)O_(15):Zr plates approximately 50 nm in thickness.The nitridation completely transformed Sr_(5)Nb_(4)O_(15):Zr to 2D single-crystalline SrNbO_(2) N:Zr with a large surface area,which was subsequently used to fabricate a thin and uniform photoanode by the spin coating method.As a result,the Co(OH)_(x)/SrNbO_(2) N:Zr/FTO photoanode capable of absorbing visible light of up to 680 nm exhibited an activity of 2.0 mA cm^(-2) at 1.23 V vs the reversible hydrogen electrode for water splitting under AM 1.5G simulated sunlight.This improvement in photoactivity mainly originated from the 2D surface morphology of SrNbO_(2) N:Zr,which is clearly distinguishable from 3D-type oxynitrides.According to electrochemical analyses,the 2D structure of SrNbO_(2) N:Zr boosted the separation and accelerated the transfer of charges photogenerated during the water splitting,thus driving the reaction further.Therefore,the result empirically demonstrates that controlling the surface morphology of SrNbO_(2) N is an effective strategy to suppress the recombination of charges and minimize their diffusion pathway,eventually enhancing the PEC activity.
基金supported by the National Natural Science Foundation of China (22168040 and 22162025)the Graduate Education Innovation Program of Yan’an University。
文摘The interfacial electric field(IEF) determines the charge carriers transport and the reactivity of heterostructure photocatalyts.Nonetheless, the restricted IEF lead to inefficient interfacial charge transport and oriented accumulation, resulting in low photocatalytic efficiency. Herein, a interfacial chemical-bonded Ti-Bi OBr/1T-Mo S_(1.85)Ohm junction is fabricated via electrostatic self-assembly strategy, in which Ti doping precisely regulates the local electrical structure and work function of Bi OBr,thus boosting the IEF to efficiently drive charge transfer and oriented accumulation to active sites. The femtosecond transient absorption spectroscopy verified that the Ti_(0.1)Bi_(0.9)OBr/1T-Mo S_(1.85)-6% increased the shallow electron trapping(τ_(1)= 0.57 ps)while the depressed recombination of photoinduced electrons with trapped holes(τ_(2)= 71.88 ps) compared to the Bi OBr/1TMo S_(1.85)-6%(τ_(1)= 0.78 ps, τ_(2)= 54.61 ps). More Importantly, the interfacial charge carriers transfer from Ti_(0.1)Bi_(0.9)OBr to 1TMoS_(1.85)(τ_(3)= 86.53 ps) was significantly accelerated by the reinforced IEF compared to Bi OBr/1T-MoS_(1.85)-6%(τ_(3)= 221.51 ps).The N_(2)-to-NH3conversion rate of Ti_(0.1)Bi_(0.9)OBr/1T-Mo S_(1.85)-6% Ohm junction(36.8 μmol g_(cat)^(-1)h^(-1)) was 1.9 and 6.9-fold higher than that of Bi OBr/1T-Mo S_(1.85)-6% and 1T-Mo S_(1.85), respectively. This work provides a new insight into the design of Ohm junction with reinforced IEF for efficient interfacial charge carrier transfer and oriented accumulation towards efficient N_(2)fixation.
基金the Fundamental Research Center of Artificial Photosynthesis(FReCAP)and financially supported by National Natural Science Foundation of China under grand no.22088102P.Fu acknowledges the financial support from Dalian Institute of Chemical Physics under grand No.DICPI202329the Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy(Innovation Fund Project No.SKLPCU24OP007).
文摘SnSe has received significant attention due to its exceptional optoelectronic and thermoelectric properties,making it a promising candidate for energy conversion applications.To exploit its potential for photo-thermoelectric applications,it is essential to prepare high-quality SnSe single-crystal films and investigate their intrinsic properties and local structure.In this work,pure and Na,Cu doped SnSe films were prepared via pulsed laser deposition(PLD).Orthorhombic SnSe films were successfully deposited along the[100]direction on SrTiO_(3)substrates.Our results show that the growth mode of SnSe films transitions from island-by-layer to 3D island growth as the film thickness increases.Notably,SnSe doped with Na and Cu restores a flatter surface even at larger thicknesses,and the current output of the Na and Cu doped SnSe film under optical and thermal excitations exhibited a significant improvement compared to the individual photo-induced and thermal-induced,as well as the sum of both,highlighting its potential for integrated photoelectric-thermoelectric applications.
基金financial support by the Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi(OIT)Shanxi Province Hundred Talent Project
文摘In recent decade, Au nanoclusters of atomic precision （AunLm, where L= organic ligand： thiolate andphosphine） have been shown as a new promising nanogold catalyst. The well-defined AunLm catalystspossess unique electronic properties and frameworks, providing an excellent opportunity to correlate theintrinsic catalytic behavior with the cluster＇s framework as well as to study the catalytic mechanismsover gold nanoclusters. In this review, we only demonstrate the important roles of the gold nanoclustersin the oxygen activation （e.g., 302 to 102） and their selective oxidations in the presence of oxygen （e.g., COto C02, sulfides to sulfoxides, alcohol to aldehyde, styrene to styrene epoxide, amines to imines, andglucose to gluconic acid）. The size-specificity （Au25 （1.3 nm）, Au38 （].5 nm）, Au144 （1.9 nm）, etc.）, ligandengineering （e.g., aromatic vs aliphatic）, and doping effects （e.g., copper, silver, palladium, and platinum）are discussed in details. Finally, the proposed reactions＇ mechanism and the relationships of clusters＇structure and activity at the atomic level also are presented.
