Altermagnets represent a newly discovered class of magnetically ordered materials.Among all the candidates,CrSb stands out due to its largest spin splitting energy and highest Néel temperature exceeding 700 K,mak...Altermagnets represent a newly discovered class of magnetically ordered materials.Among all the candidates,CrSb stands out due to its largest spin splitting energy and highest Néel temperature exceeding 700 K,making it promising for room-temperature spintronic applications.Here we have successfully grown high quality CrSb(100)thin film on GaAs(110)substrate by molecular beam epitaxy.Using angle-resolved photoemission spectroscopy,we successfully obtained the three-dimensional electronic structure of the thin film.Moreover,we observed the emergence of the altermagnetic splitting bands corresponding to the calculated results along the low symmetry pathsT-QandP-D.The bands near the Fermi level are only spin splitting bands along theP-Ddirection,with splitting energy reaching as high as 910 meV.This finding provides insights into the magnetic properties of CrSb thin films and paves the way for further studies on their electronic structure and potential applications in spintronics.展开更多
We report the observation of Zeeman splitting in multiple spectral lines emitted by a laser-produced,magnetized plasma(1–3×10^(18)cm^(-3),1–15 eV)in the context of a laboratory astrophysics experiment under a c...We report the observation of Zeeman splitting in multiple spectral lines emitted by a laser-produced,magnetized plasma(1–3×10^(18)cm^(-3),1–15 eV)in the context of a laboratory astrophysics experiment under a controlled magneticfield up to 20T.Nitrogen lines(NII)in the visible range were used to diagnose the magneticfield and plasma conditions.This was performed by coupling our data with(563–574 nm)the Stark–Zeeman line-shape code PPPB.The excellent agreement between experiment and simulations paves the way for a non-intrusive experimental platform to get time-resolved measurements of the local magneticfield in laboratory plasmas.展开更多
CuBi_(2)O_(4)is identified as a promising photocathode in photoelectrochemical(PEC)water splitting systems.However,the PEC performance of CuBi_(2)O_(4)is far from expected due to the limited separation and transport e...CuBi_(2)O_(4)is identified as a promising photocathode in photoelectrochemical(PEC)water splitting systems.However,the PEC performance of CuBi_(2)O_(4)is far from expected due to the limited separation and transport efficiency of photogenerated carriers.To address the above issues,a cost-effective ternary Cu:NiO_(X)/CuBi_(2)O_(4)/CuO composite photocathode was designed.Firstly,a thin Cu:NiO_(X)film was inserted between CuBi_(2)O_(4)and FTO conducting substrate as a hole-selective layer,which promotes the transmission of photogenerated holes to the FTO substrate effectively.Furthermore,the modification of CuO film on the CuBi_(2)O_(4)electrode not only increases the absorption of sunlight and generates more photogenerated carriers,but also constitutes a heterojunction with CuBi_(2)O_(4),creating a built-in electric field,which facilitates the separation of electrons and holes,and accelerates the electrons transfer to electrode–electrolyte interface.The fabricated Cu:NiO_(X)/CuBi_(2)O_(4)/CuO composite photocathode exhibits a surprisingly high photocurrent density of−1.51 mA·cm^(−2)at 0.4 V versus RHE,which is 2.6 times that of the pristine CuBi_(2)O_(4)photocathode.The improved PEC performance is attributed to the synergy effect of the Cu:NiO_(X)hole-selective layer and the CuBi_(2)O_(4)/CuO heterojunction.Moreover,the combination with the BiVO_(4)/CoS,an unbiased overall water splitting was achieved,which has a photocurrent of 0.193 mA·cm^(−2).展开更多
Altermagnets,a class of unconventional antiferromagnets with non-relativistic spin-splitting,offer promising potential for antiferromagnetic spintronic devices.While many altermagnets are limited by either low magneti...Altermagnets,a class of unconventional antiferromagnets with non-relativistic spin-splitting,offer promising potential for antiferromagnetic spintronic devices.While many altermagnets are limited by either low magnetic transition temperatures or weak spin splitting,the recently discovered metal CrSb,with high N′eel temperature(T_(N)=710 K)and significant spin-splitting due to its unique spin space group,provides a robust platform for remarkable tunneling magnetoresistance(TMR)in collinear all-antiferromagnetic tunnel junctions(AATJs).This study systematically investigates the spin-polarized Fermi surface of CrSb and spin-dependent electron transport in CrSb-based AATJs.The CrSb/β-InSe/CrSb junction with a three-monolayer InSe barrier exhibits a TMR ratio of approximately 290%,with energy-dependent analysis revealing TMR ratios that may exceed 850%when considering the shift of the Fermi energy.We also demonstrate the angle-dependent TMR of CrSb-based AATJs by adjusting N′eel vector orientations.Our findings might provide strong theoretical support for CrSb as a versatile building block for all-antiferromagnetic memory devices.展开更多
Green hydrogen from water splitting has emerged as a critical energy vector with the potential to spearhead the global transition to a fossil fuel-independent society.The field of catalysis has been revolutionized by ...Green hydrogen from water splitting has emerged as a critical energy vector with the potential to spearhead the global transition to a fossil fuel-independent society.The field of catalysis has been revolutionized by single-atom catalysts(SACs),which exhibit unique and intricate interactions between atomically dispersed metal atoms and their supports.Recently,bimetallic SACs(bimSACs)have garnered significant attention for leveraging the synergistic functions of two metal ions coordinated on appropriately designed supports.BimSACs offer an avenue for rich metal–metal and metal–support cooperativity,potentially addressing current limitations of SACs in effectively furnishing transformations which involve synchronous proton–electron exchanges,substrate activation with reversible redox cycles,simultaneous multi-electron transfer,regulation of spin states,tuning of electronic properties,and cyclic transition states with low activation energies.This review aims to encapsulate the growing advancements in bimSACs,with an emphasis on their pivotal role in hydrogen generation via water splitting.We subsequently delve into advanced experimental methodologies for the elaborate characterization of SACs,elucidate their electronic properties,and discuss their local coordination environment.Overall,we present comprehensive discussion on the deployment of bimSACs in both hydrogen evolution reaction and oxygen evolution reaction,the two half-reactions of the water electrolysis process.展开更多
This study presents a novel method to fabricate metal-decorated,sulfur-doped layered double hydroxides(M/SLDH)through spontaneous redox and sulfurization processes.The developed Ag/SLDH and Pt/SLDH catalysts with abun...This study presents a novel method to fabricate metal-decorated,sulfur-doped layered double hydroxides(M/SLDH)through spontaneous redox and sulfurization processes.The developed Ag/SLDH and Pt/SLDH catalysts with abundant heterogeneous interfaces and hierarchical nanostructures demonstrated outstanding oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)performance,achieving low overpotentials of 212 and 35 mV at 10 mA cm^(-2)in 1 M KOH,respectively.As both anode and cathode in water splitting,they required only 1.47 V to reach 10 mA cm^(-2)and exhibited high structural robustness,maintaining stability at 1000 mA cm^(-2)for 300 h.In-situ Raman analysis revealed that the synergistic effects of metal nanoparticles and S doping significantly promote the transformation into the S-Co1-xFexOOH layer,which serves as the active phase for water oxidation.Additionally,ultraviolet photoelectron spectroscopy(UPS)and density functional theory(DFT)analyses indicated that incorporating metal nanoparticles and S doping increase electron density near the Fermi level and reduce reaction energy barriers,thus enhancing intrinsic OER and HER activities.This study provides a scalable strategy for synthesizing high-performance electrocatalysts for water splitting,with promising potential for broader applications.展开更多
The stability and electrocatalytic efficiency of transition metal oxides for water splitting is determined by geometric and electronic structure,especially under high current densities.Herein,a newly designed lamella-...The stability and electrocatalytic efficiency of transition metal oxides for water splitting is determined by geometric and electronic structure,especially under high current densities.Herein,a newly designed lamella-heterostructured nanoporous CoFe/CoFe_(2)O_(4) and CeO_(2−x),in situ grown on nickel foam(NF),holds great promise as a high-efficient bifunctional electrocatalyst(named R-CoFe/Ce/NF)for water splitting.Experimental characterization verifies surface reconstruction from CoFe alloy/oxide to highly active CoFeOOH during in situ electrochemical polarization.By virtues of three-dimensional nanoporous architecture and abundant electroactive CoFeOOH/CeO_(2−x) heterostructure interfaces,the R-CoFe/Ce/NF electrode achieves low overpotentials for oxygen evolution(η_(10)=227 mV;η_(500)=450 mV)and hydrogen evolution(η_(10)=35 mV;η_(408)=560 mV)reactions with high normalized electrochemical active surface areas,respectively.Additionally,the alkaline full water splitting electrolyzer of R-CoFe/Ce/NF||R-CoFe/Ce/NF achieves a current density of 50 mA·cm^(−2) only at 1.75 V;the decline of activity is satisfactory after 100-h durability test at 300 mA·cm^(−2).Density functional theory also demonstrates that the electron can transfer from CeO_(2−x) by virtue of O atom to CoFeOOH at CoFeOOH/CeO_(2−x) heterointerfaces and enhancing the adsorption of reactant,thus optimizing electronic structure and Gibbs free energies for the improvement of the activity for water splitting.展开更多
Direct seawater splitting has emerged as a popular and promising research direction for synthesising clean,green,non-polluting,and sustainable hydrogen energy without depending on high-purity water in the face of the ...Direct seawater splitting has emerged as a popular and promising research direction for synthesising clean,green,non-polluting,and sustainable hydrogen energy without depending on high-purity water in the face of the world’s shortage of fossil energy.However,efficient seawater splitting is hindered by slow kinetics caused by the ultra-low conductivity and the presence of bacteria,microorganisms,and stray ions in seawater.Additionally,producing hydrogen on an industrial scale is challenging due to the high production cost.The present review addresses these challenges from the catalyst point of view,namely,that designing catalysts with high catalytic activity and stability can directly affect the rate and effect of seawater splitting.From the ion transfer perspective,designing membranes can block harmful ions,improving the stability of seawater splitting.From the energy point of view,mixed seawater systems and self-powered systems also provide new and low-energy research systems for seawater splitting.Finally,ideas and directions for further research on direct seawater splitting in the future are pointed out,with the aim of achieving low-cost and high-efficiency hydrogen production.展开更多
The electron configuration of the active sites can be effectively modulated by regulating the inherent nanostructure of the electrocatalysts,thereby enhancing their electrocatalytic performance.To tackle the unexplore...The electron configuration of the active sites can be effectively modulated by regulating the inherent nanostructure of the electrocatalysts,thereby enhancing their electrocatalytic performance.To tackle the unexplored challenge of substantial electrochemical overpotential,surface reconstruction has emerged as a necessary strategy.Focusing on key aspects such as Janus structures,overflow effects,the d-band center displacement hypothesis,and interface coupling related to electrochemical reactions is essential for water electrolysis.Emerging as frontrunners among next-generation electrocatalysts,Mott-Schottky(M-S)catalysts feature a heterojunction formed between a metal and a semiconductor,offering customizable and predictable interfacial synergy.This review offers an in-depth examination of the processes driving the hydrogen and oxygen evolution reactions(HER and OER),highlighting the benefits of employing nanoscale transition metal nitrides,carbides,oxides,and phosphides in M-S heterointerface catalysts.Furthermore,the challenges,limitations,and future prospects of employing M-S heterostructured catalysts for water splitting are thoroughly discussed.展开更多
The unavailability of high-performance and cost-effective electrocatalysts has impeded the large-scale deployment of alkaline water electrolyzers.Professor Zidong Wei's group has focused on resolving critical chal...The unavailability of high-performance and cost-effective electrocatalysts has impeded the large-scale deployment of alkaline water electrolyzers.Professor Zidong Wei's group has focused on resolving critical challenges in industrial alkaline electrolysis,particularly elucidating hydrogen and oxygen evolution reaction(HER/OER)mechanisms while addressing the persistent activity-stability trade-off.This review summarizes their decade-long progress in developing advanced electrodes,analyzing the origins of sluggish alkaline HER kinetics and OER stability limitations.Professor Wei proposes a unifying"12345 Principle"as an optimization framework.For HER electrocatalysts,they have identified that metal/metal oxide interfaces create synergistic"chimney effect"and"local electric field enhancement effect",enhancing selective intermediate adsorption,interfacial water enrichment/reorientation,and mass transport under industrial high-polarization conditions.Regarding OER,innovative strategies,including dual-ligand synergistic modulation,lattice oxygen suppression,and self-repairing surface construction,are demonstrated to balance oxygen species adsorption,optimize spin states,and dynamically reinforce metal-oxygen bonds for concurrent activity-stability enhancement.The review concludes by addressing remaining challenges in long-term industrial durability and suggesting future research priorities.展开更多
The development of robust,cost-effective and high-performance electrocatalysts is essential for industrial-scale green hydrogen production under high-current operating conditions(>500 mA/cm^(2))to ensure both high ...The development of robust,cost-effective and high-performance electrocatalysts is essential for industrial-scale green hydrogen production under high-current operating conditions(>500 mA/cm^(2))to ensure both high output and economic efficiency.Herein,a binder-free bimetallic vanadium-nickel-boride-phosphide(VNiBP)spherical electrocatalyst(SE)is synthesized via a simple hydrothermal method,followed by post-annealing.The VNiBP catalyst exhibits low overpotentials of 91 mV for the hydrogen evolution reaction(HER)and 270 mV for the oxygen evolution reaction(OER)at 100 mA/cm^(2) in 1 M KOH with stable operation over 150 h,surpassing most of the state-of-the-art electrocatalysts.The bifunctional VNiBP(-,+)exhibits a low turnover voltage of 1.57 V at 100 mA/cm^(2) and outperforms the Pt/C||RuO_(2) benchmark system up to 2000 mA/cm^(2) high-current density.The Pt/C||VNiBP hybrid configuration shows a low 2-E cell voltage of 2.55 V at 2000 mA/cm^(2) under industrially relevant conditions(6 M KOH,60℃).Notably,the VNiBP demonstrates exceptional long-term stability,maintaining continuous operation for over 6 days in both 1 M and 6 M KOH at 1000 mA/cm^(2).The outstanding overall water splitting(OWS)performance can be attributed to the synergistic combination of rapid intermediate formation,optimized adsorption/desorption kinetics,high electrochemical surface area and low charge transfer resistance offered by favorable composition and spherical morphology.展开更多
Water oxidation-a critical yet sluggish step in green hydrogen production-is a major bottleneck for electrolysis efficiency.Traditional catalysts often degrade quickly under the high current densities needed for indus...Water oxidation-a critical yet sluggish step in green hydrogen production-is a major bottleneck for electrolysis efficiency.Traditional catalysts often degrade quickly under the high current densities needed for industrial scale.展开更多
Transition metal phosphides(TMPs),with tunable electronic structures and diverse compositions,are promising candidates for electrocatalytic water splitting.However,their unsatisfactory electrical conductivity and tend...Transition metal phosphides(TMPs),with tunable electronic structures and diverse compositions,are promising candidates for electrocatalytic water splitting.However,their unsatisfactory electrical conductivity and tendency to aggregate during reactions result in structural instability,ultimately hindering further improvement of their electrocatalytic performance.To address these issues,a bamboo-leaf-like FeCoP/MXene heterojunction was synthesized by hydrothermal and thermal treatments,utilizing highly conductive MXene as the substrate.Density functional theory(DFT)calculations and experimental characterization reveal that strong Ti-O-Co/Fe covalent bond are formed between MXene and FeCoP through hybridization of O 2p and Co/Fe 3d orbitals,which enhance the structural stability of the interface and facilitate the effective anchoring of FeCoP on the MXene surface.Consequently,the structural stability and electrical conductivity of the catalyst are improved simultaneously.Additionally,interfacial charge redistribution optimizes the Gibbs free energy of hydrogen adsorption at the Co,Fe,and Ti sites while promoting the adsorption and activation of water molecules.These factors interact synergistically,leading to enhanced bi-functional electrocatalytic performance for both the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).In a FeCoP/MXene(+‖-)two-electrode system,the catalyst achieves a current density of 10 mA cm^(-2)at a potential of 1.5 V,which is superior to the RuO_(2)(+)‖Pt/C(-)system.The assembled water splitting device exhibits long-term stability for up to 100 h at a current density of 100 mA cm^(-2).Furthermore,an anion exchange membrane water electrolyzer(AEMWE)equipped with FeCoP/MXene as both anode and cathode achieves an industrial-grade current density of 500 mA cm^(-2)at 1.83 V.These results highlight the critical role of interfacial engineering in enhancing the electrocatalytic performance of TMPs for water splitting and provide valuable insights for the design of novel bifunctional TMP catalysts.展开更多
Developing BiVO_(4)photoanode with efficient carrier transfer and fast water oxidation kinetics is the permanent pursuit to achieve the state-of-art solar-driven photoelectrochemical(PEC)water splitting.The capacity t...Developing BiVO_(4)photoanode with efficient carrier transfer and fast water oxidation kinetics is the permanent pursuit to achieve the state-of-art solar-driven photoelectrochemical(PEC)water splitting.The capacity to increase the PEC activity of BiVO_(4)by loading oxygen evolution co-catalysts(OECs)has been proven,however it suffers from sluggish charge carriers dynamics brought on by the complicated interface between BiVO_(4)and OECs as well as poor long-term durability.Herein,we connected OECs(NiFeOx)and photoanode with a Al-O bridge for bettering the PEC performance of BiVO_(4).The Al-O bridge served as a channel to extract hole from BiVO_(4)to Ni Fe Ox,thus boosting charge carriers separation and preventing BiVO_(4) from photo-corrosion.The Al-O bridging photoanode(NiFeO_(x)/Al_(2)O_(3)/BiVO_(4))demonstrated a high photocurrent density of 5.87 m A/cm^(2)at 1.23 V vs.RHE and long-term photostability in comparison to Ni Fe Ox/BiVO_(4)photoanode.This study proposes a unique technique to boost charge carriers separation between BiVO_(4) and OECs for high-efficiency solar-driven PEC water splitting.展开更多
The development of stable and efficient non-noble metal cocatalysts has arisen as a promising yet challenging endeavor in the context of photocatalytic overall water splitting.In this study,NiCo alloy cocatalysts were...The development of stable and efficient non-noble metal cocatalysts has arisen as a promising yet challenging endeavor in the context of photocatalytic overall water splitting.In this study,NiCo alloy cocatalysts were synthesized with nickel/cobalt metal organic framework(NiCo-MOF)as source of nickel and cobalt.Systematic characterization results demonstrate the successful deposition of alloy cocatalysts onto the surface of SrTiO_(3).The prepared SrTiO_(3)loaded NiCo-alloy can generate hydrogen and oxygen in a stoichiometric ratio for photocatalytic overall water splitting,achieving an apparent quantum yield of 11.9%at 350±10 nm.Theoretical calculations indicate that the introduction of cobalt has a beneficial regulatory effect on the hydrogen evolution sites of Ni,reducing the free energy of H adsorption.The synergistic catalytic effect of bimetallic catalysts contributes to enhancing photocatalytic activity and stability.This study offers constructive insights for the development of high-efficiency and cost-effective cocatalyst systems.展开更多
The reasonable design of material morphology and eco-friendly electrocatalysts are essential to highly efficient water splitting.It is proposed that a promising strategy effectively regulates the electronic structure ...The reasonable design of material morphology and eco-friendly electrocatalysts are essential to highly efficient water splitting.It is proposed that a promising strategy effectively regulates the electronic structure of the d-orbitals of CoP using cerium doping in this paper,thus significantly improving the intrinsic property and conductivity of CoP for water splitting.As a result,the as-synthesize porous Ce-doped CoP micro-polyhedron composite derived from Ce-ZIF-67 as bifunctional electrocatalytic materials exhibits excellent electrocatalytic performance in both the oxygen evolution reaction(OER)and the hydrogen evolution reaction(HER),overpotentials of about 152 mV for HER at 10 mA cm^(-2)and about 352 mV for OER at 50 mA cm^(-2),and especially it shows outstanding long-term stability.Besides,an alkaline electrolyzer,using Ce0.04Co0.96P electrocatalyst as both the anode and cathode,delivers a cell voltage value of1.55 V at the current density of 10 mA cm^(-2).The calculation results of the density functional theory(DFT)demonstrate that the introduction of an appropriate amount of Ce into CoP can enhance the conductivity,and can induce the electronic modulation to regulate the selective adsorption of reaction intermediates on catalytic surface and the formation of O*intermediates(CoOOH),which exhibits an excellent electrocatalytic performance.This study provides novel insights into the design of an extraordinary performance water-splitting of the multicomponent electrocatalysts.展开更多
Green hydrogen is crucial for advancing renewable energy technologies and protecting the environment.This study introduces a controllable method for bimetallic nickel-cobalt phosphide on reduced graphene oxide on nick...Green hydrogen is crucial for advancing renewable energy technologies and protecting the environment.This study introduces a controllable method for bimetallic nickel-cobalt phosphide on reduced graphene oxide on nickel foam(NiCo_(3)P.C/NF).The material demonstrated low overpotentials of 58 and 180 mV at10 mA cm^(-2)for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)in 1.0 M KOH.It achieved excellent electrochemical water-splitting performance with operating voltages of 1.54 and 2.6 V at 10 and 500 mA cm^(-2),respectively.The overall water-splitting performance of NiCo_(3).C/NF was extremely stable after 75 h of operation at 53 mA cm^(-2),retaining 98%efficiency,better than the sample Pt-C+RuO_(2),and outperforming previous reports.Density functional theory(DFT)results revealed a synergistic NiCo_(3)P.C interaction that yields nearly zero Gibbs free energy change(-0.100 eV)and upshift d-band center,the real active site at the Ni in HER,and the lowest overpotentials 0.26 V at the P active sites for OER.Furthermore,electronic charge distribution shows the maximum charge distribution between the NiCo_(3)P phase and graphene sheet heterojunction,enhancing the electrocatalyst conductivity.This combined approach offers an innovative strategy to design sustainable electrocatalysts for water s plitting.展开更多
The quest for sustainable energy solutions has intensified the need for efficient water electrolysis techniques,pivotal for hydrogen production.However,developing effective bifunctional electrocatalysts capable of dri...The quest for sustainable energy solutions has intensified the need for efficient water electrolysis techniques,pivotal for hydrogen production.However,developing effective bifunctional electrocatalysts capable of driving the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)remains a formidable challenge.Addressing this,we introduce a novel built-in electric field(BEF)strategy to synthesize NiCoP–Co nanoarrays directly on Ti_(3)C_(2)T_(x) MXene substrates(NiCoP–Co/MXene).This approach leverages a significant work function difference(ΔΦ),propelling these nanoarrays as adept bifunctional electrocatalysts for comprehensive water splitting.MXene,in this process,plays a dual role.It acts as a conductive support,enhancing the catalyst’s overall conductivity,and facilitates an effective charge transport pathway,ensuring efficient charge transfer.Our study reveals that the BEF induces an electric field at the interface,prompting charge transfer from Co to NiCoP.This transfer modulates asymmetric charge distributions,which intricately control intermediates’adsorption and desorption dynamics.Such regulation is crucial for enhancing the reaction kinetics of both HER and OER.Furthermore,under oxidative conditions,the NiCoP–Co/MXene catalyst undergoes a structural metamorphosis into Ni(Co)oxides/hydroxides/MXene,increasing OER performance.This research demonstrates the BEF’s role in fine-tuning interfacial charge redistribution and underscores its potential in crafting more sophisticated electrocatalytic designs.The insights gained here could pave the way for the next generation of electrocatalysis,with far-reaching implications for energy conversion and storage technologies.展开更多
Hydrogen has emerged as a promising clean energy carrier,and the development of cost-effective electrocatalysts that retain high activity under acidic media is crucial for advancing proton exchange membrane water elec...Hydrogen has emerged as a promising clean energy carrier,and the development of cost-effective electrocatalysts that retain high activity under acidic media is crucial for advancing proton exchange membrane water electrolysis(PEMWE).Here,we propose the SiO_(x)/RuCoO_(x)nanoparticles(SiO_(x)/RuCoO_(x)NPs)as bifunctional electrocatalysts for efficient hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)under acidic media.The Ru-O-Si interface,along with charge transfer between Ru and Co,modulates the d-band electronic structure of the Ru site,achieving superior performance with a low HER overpotential of 18 mV at 10 mA cm^(-2)and a turnover frequency of 8.86 H_(2)s^(-1)at 100 mV.For OER,the overpotential is 217 mV at 10 mA cm^(-2).SiO_(x)/RuCoO_(x)NPs exhibit a cell voltage of 1.482 V at 10 mA cm^(-2)with an energy conversion efficiency of 83.0%.This work takes a significant step toward achieving efficient and cost-effective bifunctional electrocatalysts for water splitting,playing a critical role in the transition to clean energy technologies.展开更多
The fused quartz hemispherical resonator is the core component of the hemispherical resonator gyroscope.It features a complex shape and is Made from a Material that is difficult to process.Scratches are easily introdu...The fused quartz hemispherical resonator is the core component of the hemispherical resonator gyroscope.It features a complex shape and is Made from a Material that is difficult to process.Scratches are easily introduced during grinding,potentially degrading the mass-stiffness-damping symmetry;however,the underlying mechanisms of this influence have not been fully understood.This paper aims to investigate the effects of scratch defects on the frequency splitting and quality factor of the hemispherical resonator.First,finite element models of the hemispherical resonator with scratches are established.Then,the effects of the mass-stiffness factor,as well as the latitude and length of the scratches,on frequency splitting are analyzed.Furthermore,the impacts of latitude,length,and the first four harmonics of the unbalanced mass caused by scratches on thermoelastic damping and anchor loss are examined.Simulation results indicate that scratches above 55°latitude cause frequency splitting solely due to stiffness changes.Frequency splitting caused by scratches of the same size on the inherent rigidity shaft at the rim is approximately 50%of that near the transition fillet.Frequency splitting varies linearly with the volume of material removed by scratches.Scratches have little effect on thermoelastic damping.The first three harmonics of the unbalanced mass due to scratches at the rim are the primary contributors to anchor loss.Finally,focused ion beam trimming experiments are conducted at different locations on the hemispherical resonator.The trends observed in the experimental results are consistent with the simulation results.This work provides guidance for evaluating the impact of scratches on the performance of hemispherical resonators and for developing appropriate trimming processes.展开更多
基金supported by the National Key R&D Program of China[Grant No.2023YFA1406304(J J)]the National Natural Science Foundation of China[Grant No.12174362(J J)]+2 种基金the Innovation Program for Quantum Science and Technology[Grant No.2021ZD0302803(D L F)]the New Cornerstone Science Foundation(D L F)Beamline 03U of the Shanghai Synchrotron Radiation Facility,which is supported by ME2 project under contract No.11227902 from the National Natural Science Foundation of China。
文摘Altermagnets represent a newly discovered class of magnetically ordered materials.Among all the candidates,CrSb stands out due to its largest spin splitting energy and highest Néel temperature exceeding 700 K,making it promising for room-temperature spintronic applications.Here we have successfully grown high quality CrSb(100)thin film on GaAs(110)substrate by molecular beam epitaxy.Using angle-resolved photoemission spectroscopy,we successfully obtained the three-dimensional electronic structure of the thin film.Moreover,we observed the emergence of the altermagnetic splitting bands corresponding to the calculated results along the low symmetry pathsT-QandP-D.The bands near the Fermi level are only spin splitting bands along theP-Ddirection,with splitting energy reaching as high as 910 meV.This finding provides insights into the magnetic properties of CrSb thin films and paves the way for further studies on their electronic structure and potential applications in spintronics.
基金supported by grants managed by l’Agence Nationale de la Recherche under the Investissements d’Avenir programs Grant Nos. ANR-18-EURE-0014, ANR-10-LABX-0039-PALM, and ANR-22-CE30-0044supported by grants from Japan Society for the Promotion of Science (JSPS) KAKENHI (Grant No. 23K20038)+2 种基金JSPS Core-to-Core program (Grant No. JPJSCCA20230003)carried out within the framework of the EUROfusion Consortium, funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No. 101052200-EUROfusion)operated within the framework of the Enabling Research Project No. AWP24-ENR-IFE.02.CEA-01 “Magnetized ICF”
文摘We report the observation of Zeeman splitting in multiple spectral lines emitted by a laser-produced,magnetized plasma(1–3×10^(18)cm^(-3),1–15 eV)in the context of a laboratory astrophysics experiment under a controlled magneticfield up to 20T.Nitrogen lines(NII)in the visible range were used to diagnose the magneticfield and plasma conditions.This was performed by coupling our data with(563–574 nm)the Stark–Zeeman line-shape code PPPB.The excellent agreement between experiment and simulations paves the way for a non-intrusive experimental platform to get time-resolved measurements of the local magneticfield in laboratory plasmas.
基金supported by the National Natural Science Foundation of China(No.61804039)the University Natural Sciences Research Project of Anhui Province(No.2022AH010096)+1 种基金the Talent Research Fund of Hefei University(No.20RC35)the Natural Science Foundation of Anhui Higher Education Institution of China(No.2023AH040160).
文摘CuBi_(2)O_(4)is identified as a promising photocathode in photoelectrochemical(PEC)water splitting systems.However,the PEC performance of CuBi_(2)O_(4)is far from expected due to the limited separation and transport efficiency of photogenerated carriers.To address the above issues,a cost-effective ternary Cu:NiO_(X)/CuBi_(2)O_(4)/CuO composite photocathode was designed.Firstly,a thin Cu:NiO_(X)film was inserted between CuBi_(2)O_(4)and FTO conducting substrate as a hole-selective layer,which promotes the transmission of photogenerated holes to the FTO substrate effectively.Furthermore,the modification of CuO film on the CuBi_(2)O_(4)electrode not only increases the absorption of sunlight and generates more photogenerated carriers,but also constitutes a heterojunction with CuBi_(2)O_(4),creating a built-in electric field,which facilitates the separation of electrons and holes,and accelerates the electrons transfer to electrode–electrolyte interface.The fabricated Cu:NiO_(X)/CuBi_(2)O_(4)/CuO composite photocathode exhibits a surprisingly high photocurrent density of−1.51 mA·cm^(−2)at 0.4 V versus RHE,which is 2.6 times that of the pristine CuBi_(2)O_(4)photocathode.The improved PEC performance is attributed to the synergy effect of the Cu:NiO_(X)hole-selective layer and the CuBi_(2)O_(4)/CuO heterojunction.Moreover,the combination with the BiVO_(4)/CoS,an unbiased overall water splitting was achieved,which has a photocurrent of 0.193 mA·cm^(−2).
基金supported by the National Natural Science Foundation of China(Grant Nos.T2394475,T2394470,T2394471,and 12174129)the China Postdoctoral Science Foundation(Grant No.2023M741269).
文摘Altermagnets,a class of unconventional antiferromagnets with non-relativistic spin-splitting,offer promising potential for antiferromagnetic spintronic devices.While many altermagnets are limited by either low magnetic transition temperatures or weak spin splitting,the recently discovered metal CrSb,with high N′eel temperature(T_(N)=710 K)and significant spin-splitting due to its unique spin space group,provides a robust platform for remarkable tunneling magnetoresistance(TMR)in collinear all-antiferromagnetic tunnel junctions(AATJs).This study systematically investigates the spin-polarized Fermi surface of CrSb and spin-dependent electron transport in CrSb-based AATJs.The CrSb/β-InSe/CrSb junction with a three-monolayer InSe barrier exhibits a TMR ratio of approximately 290%,with energy-dependent analysis revealing TMR ratios that may exceed 850%when considering the shift of the Fermi energy.We also demonstrate the angle-dependent TMR of CrSb-based AATJs by adjusting N′eel vector orientations.Our findings might provide strong theoretical support for CrSb as a versatile building block for all-antiferromagnetic memory devices.
基金support from the Czech Science Foundation,project EXPRO,No 19-27454Xsupport by the European Union under the REFRESH—Research Excellence For Region Sustainability and High-tech Industries project number CZ.10.03.01/00/22_003/0000048 via the Operational Programme Just Transition from the Ministry of the Environment of the Czech Republic+1 种基金Horizon Europe project EIC Pathfinder Open 2023,“GlaS-A-Fuels”(No.101130717)supported from ERDF/ESF,project TECHSCALE No.CZ.02.01.01/00/22_008/0004587).
文摘Green hydrogen from water splitting has emerged as a critical energy vector with the potential to spearhead the global transition to a fossil fuel-independent society.The field of catalysis has been revolutionized by single-atom catalysts(SACs),which exhibit unique and intricate interactions between atomically dispersed metal atoms and their supports.Recently,bimetallic SACs(bimSACs)have garnered significant attention for leveraging the synergistic functions of two metal ions coordinated on appropriately designed supports.BimSACs offer an avenue for rich metal–metal and metal–support cooperativity,potentially addressing current limitations of SACs in effectively furnishing transformations which involve synchronous proton–electron exchanges,substrate activation with reversible redox cycles,simultaneous multi-electron transfer,regulation of spin states,tuning of electronic properties,and cyclic transition states with low activation energies.This review aims to encapsulate the growing advancements in bimSACs,with an emphasis on their pivotal role in hydrogen generation via water splitting.We subsequently delve into advanced experimental methodologies for the elaborate characterization of SACs,elucidate their electronic properties,and discuss their local coordination environment.Overall,we present comprehensive discussion on the deployment of bimSACs in both hydrogen evolution reaction and oxygen evolution reaction,the two half-reactions of the water electrolysis process.
基金National Programs for NanoKey Project(2022YFA1504002)National Natural Science Foundation of China(22078233)。
文摘This study presents a novel method to fabricate metal-decorated,sulfur-doped layered double hydroxides(M/SLDH)through spontaneous redox and sulfurization processes.The developed Ag/SLDH and Pt/SLDH catalysts with abundant heterogeneous interfaces and hierarchical nanostructures demonstrated outstanding oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)performance,achieving low overpotentials of 212 and 35 mV at 10 mA cm^(-2)in 1 M KOH,respectively.As both anode and cathode in water splitting,they required only 1.47 V to reach 10 mA cm^(-2)and exhibited high structural robustness,maintaining stability at 1000 mA cm^(-2)for 300 h.In-situ Raman analysis revealed that the synergistic effects of metal nanoparticles and S doping significantly promote the transformation into the S-Co1-xFexOOH layer,which serves as the active phase for water oxidation.Additionally,ultraviolet photoelectron spectroscopy(UPS)and density functional theory(DFT)analyses indicated that incorporating metal nanoparticles and S doping increase electron density near the Fermi level and reduce reaction energy barriers,thus enhancing intrinsic OER and HER activities.This study provides a scalable strategy for synthesizing high-performance electrocatalysts for water splitting,with promising potential for broader applications.
基金sponsored by the National Natural Science Foundation of China(Nos.5210125 and 52375422)the Science Research Project of Hebei Education Department(No.BJK2023058)the Natural Science Foundation of Hebei Province(Nos.E2020208069,B2020208083 and E202320801).
文摘The stability and electrocatalytic efficiency of transition metal oxides for water splitting is determined by geometric and electronic structure,especially under high current densities.Herein,a newly designed lamella-heterostructured nanoporous CoFe/CoFe_(2)O_(4) and CeO_(2−x),in situ grown on nickel foam(NF),holds great promise as a high-efficient bifunctional electrocatalyst(named R-CoFe/Ce/NF)for water splitting.Experimental characterization verifies surface reconstruction from CoFe alloy/oxide to highly active CoFeOOH during in situ electrochemical polarization.By virtues of three-dimensional nanoporous architecture and abundant electroactive CoFeOOH/CeO_(2−x) heterostructure interfaces,the R-CoFe/Ce/NF electrode achieves low overpotentials for oxygen evolution(η_(10)=227 mV;η_(500)=450 mV)and hydrogen evolution(η_(10)=35 mV;η_(408)=560 mV)reactions with high normalized electrochemical active surface areas,respectively.Additionally,the alkaline full water splitting electrolyzer of R-CoFe/Ce/NF||R-CoFe/Ce/NF achieves a current density of 50 mA·cm^(−2) only at 1.75 V;the decline of activity is satisfactory after 100-h durability test at 300 mA·cm^(−2).Density functional theory also demonstrates that the electron can transfer from CeO_(2−x) by virtue of O atom to CoFeOOH at CoFeOOH/CeO_(2−x) heterointerfaces and enhancing the adsorption of reactant,thus optimizing electronic structure and Gibbs free energies for the improvement of the activity for water splitting.
基金support by National Key Research and Development Program of China(2022YFB3803502)National Natural Science Foundation of China(52103076)+5 种基金Science and Technology Commission of Shanghai Municipality(23ZR1400300)special fund of Beijing Key Laboratory of Indoor Air Quality Evaluat ion and Control(NO.BZ0344KF21-02)State Key Laboratory of Electrical Insulation and Power Equipment(EIPE22203)JLF is a member of LSRE-LCM–Laboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials,supported by national funds through FCT/MCTES(PIDDAC):LSRE-LCM,UIDB/50020/2020(DOI:10.54499/UIDB/50020/2020)UIDP/50020/2020(DOI:10.54499/UIDP/50020/2020)ALiCE,LA/P/0045/2020(DOI:10.54499/LA/P/0045/2020).
文摘Direct seawater splitting has emerged as a popular and promising research direction for synthesising clean,green,non-polluting,and sustainable hydrogen energy without depending on high-purity water in the face of the world’s shortage of fossil energy.However,efficient seawater splitting is hindered by slow kinetics caused by the ultra-low conductivity and the presence of bacteria,microorganisms,and stray ions in seawater.Additionally,producing hydrogen on an industrial scale is challenging due to the high production cost.The present review addresses these challenges from the catalyst point of view,namely,that designing catalysts with high catalytic activity and stability can directly affect the rate and effect of seawater splitting.From the ion transfer perspective,designing membranes can block harmful ions,improving the stability of seawater splitting.From the energy point of view,mixed seawater systems and self-powered systems also provide new and low-energy research systems for seawater splitting.Finally,ideas and directions for further research on direct seawater splitting in the future are pointed out,with the aim of achieving low-cost and high-efficiency hydrogen production.
基金supported by the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(2021L574)the Guizhou Provincial Science and Technology Foundation([2024]ZK General 425 and 438)+1 种基金the National Natural Science Foundation of China(22309033)the Academic Young Talent Foundation of Guizhou Normal University([2022]B05 and B06)。
文摘The electron configuration of the active sites can be effectively modulated by regulating the inherent nanostructure of the electrocatalysts,thereby enhancing their electrocatalytic performance.To tackle the unexplored challenge of substantial electrochemical overpotential,surface reconstruction has emerged as a necessary strategy.Focusing on key aspects such as Janus structures,overflow effects,the d-band center displacement hypothesis,and interface coupling related to electrochemical reactions is essential for water electrolysis.Emerging as frontrunners among next-generation electrocatalysts,Mott-Schottky(M-S)catalysts feature a heterojunction formed between a metal and a semiconductor,offering customizable and predictable interfacial synergy.This review offers an in-depth examination of the processes driving the hydrogen and oxygen evolution reactions(HER and OER),highlighting the benefits of employing nanoscale transition metal nitrides,carbides,oxides,and phosphides in M-S heterointerface catalysts.Furthermore,the challenges,limitations,and future prospects of employing M-S heterostructured catalysts for water splitting are thoroughly discussed.
基金the National Key R&D Program of China(2021YFB4000300)National Natural Science Foundation of China(21822803,22408030,22072009,91534205,51072239)National Program on Key Basic Research Project(973 Program,2012CB720303).
文摘The unavailability of high-performance and cost-effective electrocatalysts has impeded the large-scale deployment of alkaline water electrolyzers.Professor Zidong Wei's group has focused on resolving critical challenges in industrial alkaline electrolysis,particularly elucidating hydrogen and oxygen evolution reaction(HER/OER)mechanisms while addressing the persistent activity-stability trade-off.This review summarizes their decade-long progress in developing advanced electrodes,analyzing the origins of sluggish alkaline HER kinetics and OER stability limitations.Professor Wei proposes a unifying"12345 Principle"as an optimization framework.For HER electrocatalysts,they have identified that metal/metal oxide interfaces create synergistic"chimney effect"and"local electric field enhancement effect",enhancing selective intermediate adsorption,interfacial water enrichment/reorientation,and mass transport under industrial high-polarization conditions.Regarding OER,innovative strategies,including dual-ligand synergistic modulation,lattice oxygen suppression,and self-repairing surface construction,are demonstrated to balance oxygen species adsorption,optimize spin states,and dynamically reinforce metal-oxygen bonds for concurrent activity-stability enhancement.The review concludes by addressing remaining challenges in long-term industrial durability and suggesting future research priorities.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.RS-2018-NR031063)in part by the research grant of Kwangwoon University in 2025.
文摘The development of robust,cost-effective and high-performance electrocatalysts is essential for industrial-scale green hydrogen production under high-current operating conditions(>500 mA/cm^(2))to ensure both high output and economic efficiency.Herein,a binder-free bimetallic vanadium-nickel-boride-phosphide(VNiBP)spherical electrocatalyst(SE)is synthesized via a simple hydrothermal method,followed by post-annealing.The VNiBP catalyst exhibits low overpotentials of 91 mV for the hydrogen evolution reaction(HER)and 270 mV for the oxygen evolution reaction(OER)at 100 mA/cm^(2) in 1 M KOH with stable operation over 150 h,surpassing most of the state-of-the-art electrocatalysts.The bifunctional VNiBP(-,+)exhibits a low turnover voltage of 1.57 V at 100 mA/cm^(2) and outperforms the Pt/C||RuO_(2) benchmark system up to 2000 mA/cm^(2) high-current density.The Pt/C||VNiBP hybrid configuration shows a low 2-E cell voltage of 2.55 V at 2000 mA/cm^(2) under industrially relevant conditions(6 M KOH,60℃).Notably,the VNiBP demonstrates exceptional long-term stability,maintaining continuous operation for over 6 days in both 1 M and 6 M KOH at 1000 mA/cm^(2).The outstanding overall water splitting(OWS)performance can be attributed to the synergistic combination of rapid intermediate formation,optimized adsorption/desorption kinetics,high electrochemical surface area and low charge transfer resistance offered by favorable composition and spherical morphology.
文摘Water oxidation-a critical yet sluggish step in green hydrogen production-is a major bottleneck for electrolysis efficiency.Traditional catalysts often degrade quickly under the high current densities needed for industrial scale.
基金financially supported by the National Natural Science Foundation of China(No.22279030)the Natural Science Fund for Distinguished Young Scholars of Heilongjiang Province(No.JQ2024B003)+1 种基金Fundamental Research Funds for the Undergraduate Universities of Heilongjiang Province(No.2024-KYYWF-0122)the Project of Key Laboratory of Superlight Materials and Surface Technology of Harbin Engineering University
文摘Transition metal phosphides(TMPs),with tunable electronic structures and diverse compositions,are promising candidates for electrocatalytic water splitting.However,their unsatisfactory electrical conductivity and tendency to aggregate during reactions result in structural instability,ultimately hindering further improvement of their electrocatalytic performance.To address these issues,a bamboo-leaf-like FeCoP/MXene heterojunction was synthesized by hydrothermal and thermal treatments,utilizing highly conductive MXene as the substrate.Density functional theory(DFT)calculations and experimental characterization reveal that strong Ti-O-Co/Fe covalent bond are formed between MXene and FeCoP through hybridization of O 2p and Co/Fe 3d orbitals,which enhance the structural stability of the interface and facilitate the effective anchoring of FeCoP on the MXene surface.Consequently,the structural stability and electrical conductivity of the catalyst are improved simultaneously.Additionally,interfacial charge redistribution optimizes the Gibbs free energy of hydrogen adsorption at the Co,Fe,and Ti sites while promoting the adsorption and activation of water molecules.These factors interact synergistically,leading to enhanced bi-functional electrocatalytic performance for both the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).In a FeCoP/MXene(+‖-)two-electrode system,the catalyst achieves a current density of 10 mA cm^(-2)at a potential of 1.5 V,which is superior to the RuO_(2)(+)‖Pt/C(-)system.The assembled water splitting device exhibits long-term stability for up to 100 h at a current density of 100 mA cm^(-2).Furthermore,an anion exchange membrane water electrolyzer(AEMWE)equipped with FeCoP/MXene as both anode and cathode achieves an industrial-grade current density of 500 mA cm^(-2)at 1.83 V.These results highlight the critical role of interfacial engineering in enhancing the electrocatalytic performance of TMPs for water splitting and provide valuable insights for the design of novel bifunctional TMP catalysts.
基金financially supported by the National Natural Science Foundation of China(No.52173277)the Fundamental Research Funds for the Central Universities of Chang’an University(No.300102299304)+1 种基金the Innovative Research Team for Science and Technology of Shaanxi Province(No.2022TD-04)the open program of Key Laboratories of Fine Chemicals and Surfactants in Sichuan Provincial Universities(No.2023JXZ03)。
文摘Developing BiVO_(4)photoanode with efficient carrier transfer and fast water oxidation kinetics is the permanent pursuit to achieve the state-of-art solar-driven photoelectrochemical(PEC)water splitting.The capacity to increase the PEC activity of BiVO_(4)by loading oxygen evolution co-catalysts(OECs)has been proven,however it suffers from sluggish charge carriers dynamics brought on by the complicated interface between BiVO_(4)and OECs as well as poor long-term durability.Herein,we connected OECs(NiFeOx)and photoanode with a Al-O bridge for bettering the PEC performance of BiVO_(4).The Al-O bridge served as a channel to extract hole from BiVO_(4)to Ni Fe Ox,thus boosting charge carriers separation and preventing BiVO_(4) from photo-corrosion.The Al-O bridging photoanode(NiFeO_(x)/Al_(2)O_(3)/BiVO_(4))demonstrated a high photocurrent density of 5.87 m A/cm^(2)at 1.23 V vs.RHE and long-term photostability in comparison to Ni Fe Ox/BiVO_(4)photoanode.This study proposes a unique technique to boost charge carriers separation between BiVO_(4) and OECs for high-efficiency solar-driven PEC water splitting.
基金supported by the Basic Science Center Program for Ordered Energy Conversion of the National Natural Science Foundation of China(No.52488201)the National Natural Science Foundation of China(No.52376209)+1 种基金the China Postdoctoral Science Foundation(Nos.2020T130503 and 2020M673386)China Fundamental Research Funds for the Central Universities.
文摘The development of stable and efficient non-noble metal cocatalysts has arisen as a promising yet challenging endeavor in the context of photocatalytic overall water splitting.In this study,NiCo alloy cocatalysts were synthesized with nickel/cobalt metal organic framework(NiCo-MOF)as source of nickel and cobalt.Systematic characterization results demonstrate the successful deposition of alloy cocatalysts onto the surface of SrTiO_(3).The prepared SrTiO_(3)loaded NiCo-alloy can generate hydrogen and oxygen in a stoichiometric ratio for photocatalytic overall water splitting,achieving an apparent quantum yield of 11.9%at 350±10 nm.Theoretical calculations indicate that the introduction of cobalt has a beneficial regulatory effect on the hydrogen evolution sites of Ni,reducing the free energy of H adsorption.The synergistic catalytic effect of bimetallic catalysts contributes to enhancing photocatalytic activity and stability.This study offers constructive insights for the development of high-efficiency and cost-effective cocatalyst systems.
基金supported by the National Natural Science Foundation of China(No.12162023&52268042)Key R&D Program of Gansu Province-International Cooperation Project(No.20YF8WA064)Natural Science Foundation of Gansu Province(No.22JR5RA253).
文摘The reasonable design of material morphology and eco-friendly electrocatalysts are essential to highly efficient water splitting.It is proposed that a promising strategy effectively regulates the electronic structure of the d-orbitals of CoP using cerium doping in this paper,thus significantly improving the intrinsic property and conductivity of CoP for water splitting.As a result,the as-synthesize porous Ce-doped CoP micro-polyhedron composite derived from Ce-ZIF-67 as bifunctional electrocatalytic materials exhibits excellent electrocatalytic performance in both the oxygen evolution reaction(OER)and the hydrogen evolution reaction(HER),overpotentials of about 152 mV for HER at 10 mA cm^(-2)and about 352 mV for OER at 50 mA cm^(-2),and especially it shows outstanding long-term stability.Besides,an alkaline electrolyzer,using Ce0.04Co0.96P electrocatalyst as both the anode and cathode,delivers a cell voltage value of1.55 V at the current density of 10 mA cm^(-2).The calculation results of the density functional theory(DFT)demonstrate that the introduction of an appropriate amount of Ce into CoP can enhance the conductivity,and can induce the electronic modulation to regulate the selective adsorption of reaction intermediates on catalytic surface and the formation of O*intermediates(CoOOH),which exhibits an excellent electrocatalytic performance.This study provides novel insights into the design of an extraordinary performance water-splitting of the multicomponent electrocatalysts.
基金supported by the Regional Leading Research Center Program(2019R1A5A8080326)funding from the Basic Science Research Program(2021R1F1A1048758,2022R1I1A1A01053248)+1 种基金the Regional Innovation Strategy(RIS)(2023RIS-008)through the National Research Foundation of Korea(NRF),funded by the Ministry of Educationsupported by the National Supercomputing Center,which provided supercomputing resources and technical support(TS-2024-RE-0039)。
文摘Green hydrogen is crucial for advancing renewable energy technologies and protecting the environment.This study introduces a controllable method for bimetallic nickel-cobalt phosphide on reduced graphene oxide on nickel foam(NiCo_(3)P.C/NF).The material demonstrated low overpotentials of 58 and 180 mV at10 mA cm^(-2)for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)in 1.0 M KOH.It achieved excellent electrochemical water-splitting performance with operating voltages of 1.54 and 2.6 V at 10 and 500 mA cm^(-2),respectively.The overall water-splitting performance of NiCo_(3).C/NF was extremely stable after 75 h of operation at 53 mA cm^(-2),retaining 98%efficiency,better than the sample Pt-C+RuO_(2),and outperforming previous reports.Density functional theory(DFT)results revealed a synergistic NiCo_(3)P.C interaction that yields nearly zero Gibbs free energy change(-0.100 eV)and upshift d-band center,the real active site at the Ni in HER,and the lowest overpotentials 0.26 V at the P active sites for OER.Furthermore,electronic charge distribution shows the maximum charge distribution between the NiCo_(3)P phase and graphene sheet heterojunction,enhancing the electrocatalyst conductivity.This combined approach offers an innovative strategy to design sustainable electrocatalysts for water s plitting.
基金supported by Guangdong Basic and Applied Basic Research Foundation(Nos.2021A1515010261 and 2023A1515140153)Guangdong Special Innovative Projects of General Universities(No.2022KTSCX136)+1 种基金the Major and Special Project in the Field of Intelligent Manufacturing of the Universities in Guangdong Province(No.2020ZDZX2067)the Innovative Team Project of the Universities in Guangdong Province(No.2023KCXTD035).
文摘The quest for sustainable energy solutions has intensified the need for efficient water electrolysis techniques,pivotal for hydrogen production.However,developing effective bifunctional electrocatalysts capable of driving the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)remains a formidable challenge.Addressing this,we introduce a novel built-in electric field(BEF)strategy to synthesize NiCoP–Co nanoarrays directly on Ti_(3)C_(2)T_(x) MXene substrates(NiCoP–Co/MXene).This approach leverages a significant work function difference(ΔΦ),propelling these nanoarrays as adept bifunctional electrocatalysts for comprehensive water splitting.MXene,in this process,plays a dual role.It acts as a conductive support,enhancing the catalyst’s overall conductivity,and facilitates an effective charge transport pathway,ensuring efficient charge transfer.Our study reveals that the BEF induces an electric field at the interface,prompting charge transfer from Co to NiCoP.This transfer modulates asymmetric charge distributions,which intricately control intermediates’adsorption and desorption dynamics.Such regulation is crucial for enhancing the reaction kinetics of both HER and OER.Furthermore,under oxidative conditions,the NiCoP–Co/MXene catalyst undergoes a structural metamorphosis into Ni(Co)oxides/hydroxides/MXene,increasing OER performance.This research demonstrates the BEF’s role in fine-tuning interfacial charge redistribution and underscores its potential in crafting more sophisticated electrocatalytic designs.The insights gained here could pave the way for the next generation of electrocatalysis,with far-reaching implications for energy conversion and storage technologies.
基金financially supported by the National Natural Science Foundation of China(No.61921005)the Key R&D Project of Nantong(No.GZ2024004)
文摘Hydrogen has emerged as a promising clean energy carrier,and the development of cost-effective electrocatalysts that retain high activity under acidic media is crucial for advancing proton exchange membrane water electrolysis(PEMWE).Here,we propose the SiO_(x)/RuCoO_(x)nanoparticles(SiO_(x)/RuCoO_(x)NPs)as bifunctional electrocatalysts for efficient hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)under acidic media.The Ru-O-Si interface,along with charge transfer between Ru and Co,modulates the d-band electronic structure of the Ru site,achieving superior performance with a low HER overpotential of 18 mV at 10 mA cm^(-2)and a turnover frequency of 8.86 H_(2)s^(-1)at 100 mV.For OER,the overpotential is 217 mV at 10 mA cm^(-2).SiO_(x)/RuCoO_(x)NPs exhibit a cell voltage of 1.482 V at 10 mA cm^(-2)with an energy conversion efficiency of 83.0%.This work takes a significant step toward achieving efficient and cost-effective bifunctional electrocatalysts for water splitting,playing a critical role in the transition to clean energy technologies.
基金Supported by National Key Research and Development Program of China(Grant No.2022YFB3403600)the National Natural Science Foundation of China(Grant No.52305461)。
文摘The fused quartz hemispherical resonator is the core component of the hemispherical resonator gyroscope.It features a complex shape and is Made from a Material that is difficult to process.Scratches are easily introduced during grinding,potentially degrading the mass-stiffness-damping symmetry;however,the underlying mechanisms of this influence have not been fully understood.This paper aims to investigate the effects of scratch defects on the frequency splitting and quality factor of the hemispherical resonator.First,finite element models of the hemispherical resonator with scratches are established.Then,the effects of the mass-stiffness factor,as well as the latitude and length of the scratches,on frequency splitting are analyzed.Furthermore,the impacts of latitude,length,and the first four harmonics of the unbalanced mass caused by scratches on thermoelastic damping and anchor loss are examined.Simulation results indicate that scratches above 55°latitude cause frequency splitting solely due to stiffness changes.Frequency splitting caused by scratches of the same size on the inherent rigidity shaft at the rim is approximately 50%of that near the transition fillet.Frequency splitting varies linearly with the volume of material removed by scratches.Scratches have little effect on thermoelastic damping.The first three harmonics of the unbalanced mass due to scratches at the rim are the primary contributors to anchor loss.Finally,focused ion beam trimming experiments are conducted at different locations on the hemispherical resonator.The trends observed in the experimental results are consistent with the simulation results.This work provides guidance for evaluating the impact of scratches on the performance of hemispherical resonators and for developing appropriate trimming processes.
