Developing efficient and durable alkaline hydrogen evolution reaction(HER)catalysts is crucial for realizing high-performance,practical anion exchange membrane water electrolyzer(AEMWE)operating at ampere-level curren...Developing efficient and durable alkaline hydrogen evolution reaction(HER)catalysts is crucial for realizing high-performance,practical anion exchange membrane water electrolyzer(AEMWE)operating at ampere-level current densities.Although atomically dispersed Platinum(Pt)catalysts offer significant potential for enhancing atom utilization,their HER performance and durability are limited by the inflexibility in valence electron transfer between Pt and the support.In this study,we utilize asymmetrically single-atom copper(Cu)with tunable valence states as a valence electron reservoir(VER)to dynamically regulate the Pt 5d valence states,achieving efficient alkaline HER.In situ synchrotron radiation and theoretical calculations demonstrate that the dynamic evolution of the Pt 5d valence electron configuration optimizes the adsorption strengths of reaction intermediates.Meanwhile,single-atom Cu accelerates the rate-limiting water dissociation,and Pt facilitates subsequent^(*)H coupling.The catalyst requires only 23.5 and 177.2 mV overpotentials to achieve current densities of 10 and 500 mA cm^(-2)in 1 M KOH.Notably,the PtCu/NC exhibits a~57%lower hydrogen evolution barrier than Pt/NC.Moreover,the PtCu/NC-based AEMWE operates for over 600 h at an industrially relevant current density of 500 mA cm^(-2).展开更多
The real structure and in situ evolution of catalysts under working conditions are of paramount importance,especially for bifunctional electrocatalysis.Here,we report asymmetric structural evolution and dynamic hydrog...The real structure and in situ evolution of catalysts under working conditions are of paramount importance,especially for bifunctional electrocatalysis.Here,we report asymmetric structural evolution and dynamic hydrogen-bonding promotion mechanism of an atomically dispersed electrocatalyst.Pyrolysis of Co/Ni-doped MAF-4/ZIF-8 yielded nitrogen-doped porous carbons functionalized by atomically dispersed Co–Ni dual-metal sites with an unprecedented N8V4 structure,which can serve as an efficient bifunctional electrocatalyst for overall water splitting.More importantly,the electrocatalyst showed remarkable activation behavior due to the in situ oxidation of the carbon substrate to form C–OH groups.Density functional theory calculations suggested that the flexible C–OH groups can form reversible hydrogen bonds with the oxygen evolution reaction intermediates,giving a bridge between elementary reactions to break the conventional scaling relationship.展开更多
Asymmetric single-atom catalysts(ASACs)have attracted much attention owing to their excellent catalytic properties.However,the relationship between asymmetric coordination and the spin states of metal sites remains un...Asymmetric single-atom catalysts(ASACs)have attracted much attention owing to their excellent catalytic properties.However,the relationship between asymmetric coordination and the spin states of metal sites remains unclear.Additionally,the modulation of reactive oxygen species in Fenton-like reactions remains challenging.Herein,a novel strategy is reported for the rational design of highly loaded Co ASACs(CoN_(1)C_(2)/C_(2)N)immobilized on three-dimensional flower-like C_(2)N using an in situ-generated carbon defect method.In particular,the asymmetrically tricoordinated CoN_(1)C_(2)/C_(2)N exhibited excellent catalytic activity for sulfachloropyridazine degradation,with a turnover frequency of 36.8 min^(–1).Experimental results and theoretical calculations revealed that the electron spin state of the Co-active sites was transferred from the low-spin configuration(t_(2g)^(6)e_(g)^(1))to the high-spin configuration(t_(2g)^(5)e_(g)^(2))owing to asymmetric coordination.The high-spin Co 3d orbital in CoN_(1)C_(2)/C_(2)N possessed more unpaired electrons and therefore,had a strong ability to gain electrons from the O 2p orbitals of HSO_(5)^(–),boosting d-p orbital hybridization.More importantly,the spin-electron filling in theσ^(*)orbital of high-spin Co 3d−O 2p accelerated the desorption of^(*)SO_(5)•^(−),which acted as a rate-limiting step in the reaction,thus facilitating more^(1)O_(2)generation.This study provides an innovative synthetic route for practical ASACs and clarifies the critical relationship between structure and spin state,paving the way for advancements in environmental remediation and energy conversion applications.展开更多
CO_(2)electroreduction(CO_(2)RR)represents a promising negative-carbon technology,which is in urgent need for efficient and high-selectivity catalysts.Here,a support control strategy is employed for precise surface en...CO_(2)electroreduction(CO_(2)RR)represents a promising negative-carbon technology,which is in urgent need for efficient and high-selectivity catalysts.Here,a support control strategy is employed for precise surface engineering of charge-asymmetry nanocluster catalyst(CuZnSCN),in which zinc and copper atoms together form a metal cluster loaded on sulfur and nitrogen co-etched carbon matrix.The synergistic promotion mechanism of CO_(2)RR by Cu–Zn atom interactions and sulfur–nitrogen atom doping was investigated.A CO partial current density of 74.1 mA cm^(-2)was achieved in an alkaline electrolyte,as well as a considerable CO Faraday efficiency of 97.7%.In situ XAS(X-ray absorption spectroscopy)showed that the stabilization of Cu^(+)and Zn^(2+)species in the nanoclusters and doped sulfur atoms during the CO_(2)RR process contributes to the sustained adsorption of protons and the generation and conversion of the CO.This work verifies the possibility of metal-support and intermetallic interactions to synergistically enhance electrochemical catalytic performance and provides ideas for further bimetallic cluster catalyst development.展开更多
Cu-based metal-organic frameworks(Cu-MOFs)electrocatalysts are promising for CO_(2)reduction reactions(CO_(2)RR)to produce valuable C_(2+)products.However,designing suitable active sites in Cu-MOFs remains challenging...Cu-based metal-organic frameworks(Cu-MOFs)electrocatalysts are promising for CO_(2)reduction reactions(CO_(2)RR)to produce valuable C_(2+)products.However,designing suitable active sites in Cu-MOFs remains challenging due to their inherent structural instability during CO_(2)RR.Here we propose a synergistic strategy through thermal annealing and electrochemicalactivation process for in-situ reconstruction of the pre-designed Cu-MOFs to produce abundant partially oxidized Cu(Cu^(δ+))active species.The optimized MOF-derived Cu^(δ+)electrocatalyst demonstrates a highly selective production of C_(2+)products,with the Faradaic Efficiency(FE)of 78±2%and a partial current density of-46 m A cm-2at-1.06 VRHEin a standard H-type cell.Our findings reveal that the optimized Cu^(δ+)-rich surface remains stable during electrolysis and enhances surface charge transfer,leading to an increase in the concentration of*CO intermediates,thereby highly selectively producing C_(2+)compounds.This study advances the controllable formation of MOF-derived Cu^(δ+)-rich surfaces and strengthens the understanding of their catalytic role in CO_(2)RR for C_(2+)products.展开更多
Single atom catalysts(SACs)have attracted great attention,yet the quest for highly-efficient catalysts is driven by the current obstacles of ambiguous structure-performance relationship.Here,we report a nature keratin...Single atom catalysts(SACs)have attracted great attention,yet the quest for highly-efficient catalysts is driven by the current obstacles of ambiguous structure-performance relationship.Here,we report a nature keratin-based Fe-S_(1)N_(3)SACs with ultrathin two-dimensional(2D)porous carbon nanosheets structure,by controlling the active center through the precise coordination of sulfur and nitrogen.Compared with natural silk-based Fe-N_(4) catalyst,the Fe-S_(1)N_(3)SACs exhibit excellent Fenton-like oxidation degradation ability.X-ray absorption fine structure(XAFS)and electron paramagnetic resonance(EPR)results confirm that S doping is conducive to electron transfer,to accurately generate·OH with high oxidative degradation capacity at the active site.Therefore,the optimized Fe-S_(1)N_(3)catalyst showed higher oxidation degradation activity for organic pollutant substrates(methylene blue(MB),Rhodamine B(RhB)and phenol),significantly superior to Fe-N_(4) samples.This work is devoted to the treatment and application of natural fibers,which provides a novel method for the synthesis of SACs and the regulation of atomic coordination environment.展开更多
Molecular catalysts with well-defined single atom sites and coordination environments exhibit significant potential as oxygen reduction electrocatalysts,but suffering from the activity and stability issues.Herein,the ...Molecular catalysts with well-defined single atom sites and coordination environments exhibit significant potential as oxygen reduction electrocatalysts,but suffering from the activity and stability issues.Herein,the ultrathin carbon shell supported FePc molecule electrocatalysts(FePc/TA-ONG-N),featuring with a direct oxygen bridging between FePc and carbon substrate,were designed and synthesized.The direct connection with oxygen atom on carbon substrate,certified by the Fourier transform infrared spectroscopy(FTIR)and extended X-ray absorption fine structure(EXAFS),can remarkably enhance the interaction and facilitate electron transfer from Fe,leading to an improved activity by reducing adsorption strength of intermediate species through lowering the d-band center position.The resultant half-wave potential of 0.902 V together with a Tafel slope of 23.64 mV·dec^(−1)is superior to Pt/C and control samples.Such catalyst holds a promise as air-cathode electrocatalyst in Zn-air battery with excellent operation stability exceeding 80 h.The density functional theory(DFT)calculations and molecular dynamic simulations unveiled that the O-bridge can effectively stabilize the FePc molecule and function as electron buffer to donate/gain electrons to/from Fe atom during the adsorption of oxygenates.The current findings are insightful for developing molecular catalysts with high performance through substrate engineering and axial coordination.展开更多
Elucidation of a physicochemical process on nanocatalysts,especially under continuously evolving conditions,is often heavily tool-driven because of technical challenges.Recently,ambient pressure X-ray photoelectron sp...Elucidation of a physicochemical process on nanocatalysts,especially under continuously evolving conditions,is often heavily tool-driven because of technical challenges.Recently,ambient pressure X-ray photoelectron spectroscopy(APXPS)emerges as an emerging photon-in-electron-out technique in in-situ/operando analysis by bridging the pressure-gap between conventional ultra-high vacuum(UHV)and near ambient or even close to operating conditions,rendering the advancement of XPS from a UHV-based technique to a versatile and powerful tool that enables the specific probe of numerous events taking place at the gas–solid,liquid–solid and liquid–gas nanoscale interfaces which are critical to nanocatalysis research.For example,APXPS probes information on catalytically active phase and reaction kinetics in nanocatalytic processes;details inside the electric double-layer at an electrolyte/electrode interface can now be accessed;more efficient nanocatalyst design can be achieved and energy transfer venues can be optimized.Here,we aim to critically review the recent advances in instrumentation and the probe of the gas–solid,liquid–solid,and gas–liquid nanoscale interfaces using APXPS-based methodologies,followed by putting forward an outlook of development of APXPS as a rising in-situ/operando analytical means in surface science,nanocatalysis,nanoscience materials science.展开更多
By incorporating a limited number of precious metal atoms into the base metal,the single-atom alloy catalyst not only optimizes the electronic structure and stability of the catalyst but also emerges as an innovative ...By incorporating a limited number of precious metal atoms into the base metal,the single-atom alloy catalyst not only optimizes the electronic structure and stability of the catalyst but also emerges as an innovative material that enhances the efficiency and selectivity of catalytic reactions.RuCo single-atom alloy electrocatalyst supported on S,N co-doped carbon nanosheets(RuCo SAA/SNC)uniformly distributed on nitrogen,sulfur co-doped carbon nanosheets was prepared by two-step pyrolysis and carbonization.The incorporation of Ru not only optimizes the atomic utilization of Ru but also enhances the charge conduction properties of the surface Co species,thereby increasing the evolution and migration rates of hydrogen ions.In a 0.5 M H_(2)SO_(4) solution,the RuCo SAA/SNC catalyst demonstrates a tafel slope of 27.5 mV·dec^(-1) and an overpotential of merely 43 mV at 10 mA·cm^(-2).This work achieves enhanced catalytic performance and stability by precisely regulating the atomic-level structure of single-atom alloy catalysts,thereby promoting their widespread application in energy conversion and green chemistry.展开更多
The electrocatalytic C-N coupling reaction as a green synthesis approach for C-N bond synthesis via electrochemical processes with catalytic assistance.However,inefficient reactant adsorption onto the catalyst surface...The electrocatalytic C-N coupling reaction as a green synthesis approach for C-N bond synthesis via electrochemical processes with catalytic assistance.However,inefficient reactant adsorption onto the catalyst surface,competing side reactions,and the complexity and diversity of reaction pathways hinder its widespread application.Atomically dispersed catalysts(ADCs),as an emerging class of catalytic materials,possess precisely defined active sites,high catalytic activity,and enhanced selectivity,thereby enabling efficient electrocatalytic C-N coupling to address these challenges.This review discusses current reaction pathways for converting small molecules(CO_(2)as the carbon source,N_(2),NO_(2)^(-),NO_(3)^(-)as the nitrogen source)into high-value organic nitrogen compounds(urea,amides,oximes,and amino acids)utilizing ADCs.It specifically focuses on the critical steps within electrocatalytic C-N coupling facilitated by these catalysts,encompassing reactant adsorption,transformation and selective hydrogenation of C-/N-intermediates,and the C-N coupling reaction itself.Based on these key steps,design principles for ADCs are proposed.Finally,the synthesis strategies for ADCs-vacancy engineering,confinement strategies,and alloying-are examined,alongside the mechanisms by which they enhance catalytic activity and selectivity.展开更多
Transition metal sulfides with homogeneous multi-metallic elements promise high catalytic performance for water electrolysis owing to the unique structure and highly tailorable electrochemical property.Most existing s...Transition metal sulfides with homogeneous multi-metallic elements promise high catalytic performance for water electrolysis owing to the unique structure and highly tailorable electrochemical property.Most existing synthetic routes require high temperature to ensure the uniform mixing of various elements,making the synthesis highly challenging.Here,for the first-time novel carbon fiber supported high-entropy Co-Zn-Cd-Cu-Mn sulfide(CoZnCdCuMnS@CF)nanoarrays are fabricated by the mild cation exchange strategy.Benefiting from the synergistic effect among multiple metals and the strong interfacial bonding between high-entropy Co-Zn-Cd-Cu-Mn sulfide nanoarrays and the carbon fiber support,CoZnCdCuMnS@CF exhibits superior catalytic activity and stability toward overall water splitting in alkaline medium.Impressively,CoZnCdCuMnS@CF only needs low overpotentials of 173 and 220 mV to reach the current density of 10 mA•cm^(−2),with excellent durability for over 70 and 113 h for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)respectively.More importantly,the bifunctional electrode(CoZnCdCuMnS@CF||CoZnCdCuMnS@CF)for overall water splitting can deliver a small cell voltage of 1.63 V to afford 10 mA•cm^(−2) and exhibit outstanding stability of negligible decay after 73 h continuous operation.This work provides a viable synthesis route toward advanced high-entropy materials with great potential applications.展开更多
The depletion of energy and increasing environmental pressure have become one of the main challenges in the world today.Synthetic high-efficiency catalysts bring hope for efficient conversion of energy and effective t...The depletion of energy and increasing environmental pressure have become one of the main challenges in the world today.Synthetic high-efficiency catalysts bring hope for efficient conversion of energy and effective treatment of pollutants,especially,single-atom catalysts(SACs)are promising candidates.Herein,we comprehensively summarizes the atomic diffusion strategy,which is considered as an effective method to prepare a series of SACs.According to the different diffusion forms of the precursors,we review the synthesis pathways of SACs from three aspects:gas diffusion,solid diffusion and liquid diffusion.The gaseous diffusion method mainly discusses atomic layer deposition(ALD)and chemical vapor deposition(CVD),both of which carry out gas phase mass transfer at high temperatures.The solid-state diffusion method can be divided into nanoparticle transformation into single atoms and solid atom migration.Liquid diffusion mainly describes the electrochemical method and the molten salt method.We hope this review can trigger the rational design of SACs.展开更多
Although nanozyme has become an emerging area of research attracting extensive attention recently,the activity and specificity of currently reported nanozymes are generally lower than those of natural enzymes.Developi...Although nanozyme has become an emerging area of research attracting extensive attention recently,the activity and specificity of currently reported nanozymes are generally lower than those of natural enzymes.Developing highly active and specific nanozymes is therefore extremely necessary and also remains a great challenge.Superoxide dismutase(SOD)catalyzes the disproportionation of cytotoxic O_(2)·^(−)into hydrogen peroxide and oxygen,and plays an important role in reducing human oxidative stress.In this work,we prepare Cu single-atom catalysts(Cu/GO SACs,GO=graphene oxide)through a simple and low-cost strategy at room temperature using Cu foam and graphene oxide.Cu/GO SACs can maintain excellent catalytic activity under harsh environment.Compared with the natural enzyme,SOD-like Cu/GO SAC nanozyme has higher catalytic activity and meanwhile,it does not possess the common properties of other mimic enzymes often existing in nanomaterials.Based on the excellent SOD-like enzyme activity of Cu/GO SACs,it successfully eliminates the active oxygen in cigarette smoke.This work not only provides a new idea for the design and synthesis of nanozymes with excellent SOD mimetic properties,but also is promising in the treatment of lung injury and inflammatory diseases related to free radical production.展开更多
Rational design and construction of low-cost and highly efficient electrocatalysts for hydrogen evolution reaction(HER)is meaningful but challenging.Herein,a robust three dimensional(3D)hollow CoSe_(2)@ultrathin MoSe_...Rational design and construction of low-cost and highly efficient electrocatalysts for hydrogen evolution reaction(HER)is meaningful but challenging.Herein,a robust three dimensional(3D)hollow CoSe_(2)@ultrathin MoSe_(2)core@shell heterostructure(CoSe_(2)@MoSe_(2))is proposed as an efficient HER electrocatalyst through interfacial engineering.Benefitting from the abundant heterogeneous interfaces on CoSe_(2)@MoSe_(2),the exposed edge active sites are maximized and the charge transfer at the hetero-interfaces is accelerated,thus facilitating the HER kinetics.It exhibits remarkable performance in pH-universal conditions.Notably,it only needs an overpotential(η10)of 108 mV to reach a current density of 10 mA·cm^(-2)in 1.0 M KOH,outperforming most of the reported transition metal selenides electrocatalysts.Density functional theory(DFT)calculations unveil that the heterointerfaces synergistically optimize the Gibbs free energies of H2O and H^(*)during alkaline HER,accelerating the reaction kinetics.The present work may provide new construction guidance for rational design of high-efficient electrocatalysts.展开更多
The atomic-level interfacial regulation of single metal sites through heteroatom doping can significantly improve the characteristics of the catalyst and obtain surprising activity.Herein,nickel single-site catalysts(...The atomic-level interfacial regulation of single metal sites through heteroatom doping can significantly improve the characteristics of the catalyst and obtain surprising activity.Herein,nickel single-site catalysts(SSCs)with dual-coordinated phosphorus and nitrogen atoms were developed and confirmed(denoted as Ni-PxNy,x=1,2 and y=3,2).In CO_(2)reduction reaction(CO_(2)RR),the CO current density on Ni-PxNy was significantly higher than that of Ni-N4 catalyst without phosphorus modification.Besides,Ni-P1N3 performed the highest CO Faradaic efficiency(FECO)of 85.0%–98.0%over a wide potential range of−0.65 to−0.95 V(vs.the reversible hydrogen electrode(RHE)).Experimental and theoretical results revealed that the asymmetric Ni-P1N3 site was beneficial to CO_(2)intermediate adsorption/desorption,thereby accelerating the reaction kinetics and boosting CO_(2)RR activity.This work provides an effective method for preparing well-defined dual-coordinated SSCs to improve catalytic performance,targetting to CO_(2)RR applications.展开更多
Producing hydrogen peroxide(H_(2)O_(2))through an electrochemical oxygen reduction reaction(ORR)is a safe,green strategy and a promising alternative to traditional energy-intensive anthraquinone processes.Air and rene...Producing hydrogen peroxide(H_(2)O_(2))through an electrochemical oxygen reduction reaction(ORR)is a safe,green strategy and a promising alternative to traditional energy-intensive anthraquinone processes.Air and renewable power could be utilized for onsite and decentralized H_(2)O_(2)production,demonstrating significant application potential.Currently,single atom catalysts(SACs)have demonstrated significant advantages in the catalytic production of H_(2)O_(2)in 2e−ORR.However,the selectivity of SACs in ORR once puzzled researchers.This article reviews the research on the development and achievements of H_(2)O_(2)production by SACs catalysis in recent years.Especially,the structure-performance relationship is a guide to designing new SACs.Combining advanced characterization techniques and theoretical calculation methods,researchers have a clearer and more thorough understanding of the impact of the atomic interface of SACs on ORR catalytic performance.The coordination moiety formed between the active metal center atom and the support seriously determines the selectivity of SACs,mainly manifested in the adsorption of*OOH intermediates.Particularly,the atomic interface of metal atoms together with O/N co-coordination exhibit high selectivity and mass activity,and heteroatoms or functional groups on carbon supports present synergistic effects to promote the production of H_(2)O_(2)in 2e−ORR.Fine and accurate regulation of the atomic interface of SACs directly affects the 2e−ORR performance of the catalysts.Therefore,it is important to deeply understand the atomic interface of SACs and contribute to the development of novel catalysts.展开更多
Energy transformation is imminent,and hydrogen energy is one of the important new energy sources.One of the keys to increasing the rate of hydrogen evolution during electrolysis is the use of high-performance catalyst...Energy transformation is imminent,and hydrogen energy is one of the important new energy sources.One of the keys to increasing the rate of hydrogen evolution during electrolysis is the use of high-performance catalysts for oxygen evolution reactions(OER).Single-atom alloys(SAAs)have garnered significant attention because they partially reduce costs and combine the advantages of both single-atom catalysts(SACs)and alloy catalysts.Herein,an efficient pyrolysis strategy based on a mixing and drying process is designed to anchor ultra-small Co cluster particles,combined with Ru single atoms dispersed on nitrogen-doped ultra-thin carbon nanosheets(Ru_(1)Co SAA/NC).The prepared electrocatalyst exhibits superior OER activity and superb stability,demonstrating an overpotential of 238 mV for OER with a current density of 10 mA·cm^(-2) in 0.5 mol/L H_(2)SO_(4).And we also utilized in-situ XAS to detect the oxidation state of Ru sites during OER.All in all,this method achieves cost reductions and efficiency improvements through the design of SAAs,offering new prospects for the structural transformation of clean energy.展开更多
Developing cost-effective and high-efficiency oxygen reduction reaction(ORR)catalysts is imperative for promoting the substantial progress of fuel cells and metal-air batteries.The coordination and geometric engineeri...Developing cost-effective and high-efficiency oxygen reduction reaction(ORR)catalysts is imperative for promoting the substantial progress of fuel cells and metal-air batteries.The coordination and geometric engineering of single-atom catalysts(SACs)occurred the promising approach to overcome the thermodynamics and kinetics problems in high-efficiency electrocatalysis.Herein,we rationally constructed atomically dispersed Co atoms on porous N-enriched graphene material C_(2)N(CoSA-C2N)for efficient oxygen reduction reaction(ORR).Systematic characterizations demonstrated the active sites for CoSA-C2N is as identified as coordinatively unsaturated Co-N_(2)moiety,which exhibits ORR intrinsic activity.Structurally,the porous N-enriched graphene framework in C_(2)N could effectively increase the accessibility to the active sites and promote mass transfer rate,contributing to improved ORR kinetics.Consequently,CoSA-C_(2)N exhibited superior ORR performance in both acidic and alkaline conditions as well as impressive long-term durability.The coordination and geometric engineering of SACs will provide a novel approach to advanced catalysts for energy related applications.展开更多
Interface regulation plays a key role in the electrochemical performance for biosensors.By controlling the interfacial interaction,the electronic structure of active species can be adjusted effectively at micro and na...Interface regulation plays a key role in the electrochemical performance for biosensors.By controlling the interfacial interaction,the electronic structure of active species can be adjusted effectively at micro and nano-level,which results in the optimal reaction energy barrier.Herein,we propose an interface electronic engineering scheme to design a strongly coupled 1T phase molybdenum sulfide(1T-MoS2)/MXene hybrids for constructing an efficient electrocatalytic biomimetic sensor.The local electronic and atomic structures of the 1T-MoS2/Ti3C2TX are comprehensively studied by synchrotron radiation-based X-ray photoelectron spectroscopy(XPS),as well as X-ray absorption spectroscopy(XAS)at atomic level.Experiments and theoretical calculations show that there are interfacial stresses,atomic defects and adjustable bond-length between MoS2/MXene nanosheets,which can significantly promote biomolecular adsorption and rapid electron transfer to achieve excellent electrochemical activity and reaction kinetics.The 1T-MoS2/Ti3C2TX modified electrode shows ultra high sensitivity of 1.198μA/μM for dopamine detection with low limit of 0.05μM.We anticipate that the interface electronic engineering investigation could provide a basic idea for guiding the exploration of advanced biosensors with high sensitivity and low detection limit.展开更多
Exploiting inexpensive and effective nickel-based catalysts that produce hydrogen from liquid organic hydrogen carriers(LOHCs)is crucial to alleviating the global energy and environmental crisis.In this study,we repor...Exploiting inexpensive and effective nickel-based catalysts that produce hydrogen from liquid organic hydrogen carriers(LOHCs)is crucial to alleviating the global energy and environmental crisis.In this study,we report a rational strategy that can realize atomically dispersed Ni atoms anchored on vacancy-abundant boron nitride nanosheets(Ni1/h-BNNS)with high specific surface area(up to 622 m^(2)·g^(-1))and abundant hydroxyl groups for high efficient hydrogen production.Methanol dehydrogenation results show an excellent hydrogen production performance catalyzed by this Ni1/h-BNNS,as evidenced by a remarkably high H_(2) yield rate(1684.23 mol·mol_(Ni)^(-1)·h^(-1)),nearly 100%selectivity toward hydrogen and CO,and high anti-coking performance.Density functional theory(DFT)calculations reveal that the outstanding catalytic performance of Ni1/h-BNNS primarily originates from the unique coordinated environment of atomically dispersed Ni(Ni-B_(2)O_(2))and the synergistic interaction between Ni single atoms and the h-BNNS support.Specifically,the coordinated O atoms play a decisive role in promoting the activity of Ni,and the neighboring B sites significantly decrease the energy barriers for the adsorption of key intermediates of methanol dehydrogenation.This study offers a novel strategy for developing high-performance and stable single-atom Ni catalysts by precisely controlling single-atom sites on h-BN support for sustainable hydrogen production.展开更多
基金supported by the Ningbo Top-Talent Team Program,Program for the National Natural Science Foundation of China(22106166)the Yongjiang Innovative Individual Introduction of China,and the China Postdoctoral Science Foundation(2022M723253)。
文摘Developing efficient and durable alkaline hydrogen evolution reaction(HER)catalysts is crucial for realizing high-performance,practical anion exchange membrane water electrolyzer(AEMWE)operating at ampere-level current densities.Although atomically dispersed Platinum(Pt)catalysts offer significant potential for enhancing atom utilization,their HER performance and durability are limited by the inflexibility in valence electron transfer between Pt and the support.In this study,we utilize asymmetrically single-atom copper(Cu)with tunable valence states as a valence electron reservoir(VER)to dynamically regulate the Pt 5d valence states,achieving efficient alkaline HER.In situ synchrotron radiation and theoretical calculations demonstrate that the dynamic evolution of the Pt 5d valence electron configuration optimizes the adsorption strengths of reaction intermediates.Meanwhile,single-atom Cu accelerates the rate-limiting water dissociation,and Pt facilitates subsequent^(*)H coupling.The catalyst requires only 23.5 and 177.2 mV overpotentials to achieve current densities of 10 and 500 mA cm^(-2)in 1 M KOH.Notably,the PtCu/NC exhibits a~57%lower hydrogen evolution barrier than Pt/NC.Moreover,the PtCu/NC-based AEMWE operates for over 600 h at an industrially relevant current density of 500 mA cm^(-2).
基金supported by the National Key Research and Development Program of China(2021YFA1500401)the National Natural Science Foundation of China(21890380,21975290,21901089,and 21821003)+1 种基金the Foundation of Basic and Applied Basic Research of Guangdong Province(2020B1515120024)C.-T.H.acknowledges the Jiangxi Province(20202ZDB01004 and jxsq2018106041).
文摘The real structure and in situ evolution of catalysts under working conditions are of paramount importance,especially for bifunctional electrocatalysis.Here,we report asymmetric structural evolution and dynamic hydrogen-bonding promotion mechanism of an atomically dispersed electrocatalyst.Pyrolysis of Co/Ni-doped MAF-4/ZIF-8 yielded nitrogen-doped porous carbons functionalized by atomically dispersed Co–Ni dual-metal sites with an unprecedented N8V4 structure,which can serve as an efficient bifunctional electrocatalyst for overall water splitting.More importantly,the electrocatalyst showed remarkable activation behavior due to the in situ oxidation of the carbon substrate to form C–OH groups.Density functional theory calculations suggested that the flexible C–OH groups can form reversible hydrogen bonds with the oxygen evolution reaction intermediates,giving a bridge between elementary reactions to break the conventional scaling relationship.
文摘Asymmetric single-atom catalysts(ASACs)have attracted much attention owing to their excellent catalytic properties.However,the relationship between asymmetric coordination and the spin states of metal sites remains unclear.Additionally,the modulation of reactive oxygen species in Fenton-like reactions remains challenging.Herein,a novel strategy is reported for the rational design of highly loaded Co ASACs(CoN_(1)C_(2)/C_(2)N)immobilized on three-dimensional flower-like C_(2)N using an in situ-generated carbon defect method.In particular,the asymmetrically tricoordinated CoN_(1)C_(2)/C_(2)N exhibited excellent catalytic activity for sulfachloropyridazine degradation,with a turnover frequency of 36.8 min^(–1).Experimental results and theoretical calculations revealed that the electron spin state of the Co-active sites was transferred from the low-spin configuration(t_(2g)^(6)e_(g)^(1))to the high-spin configuration(t_(2g)^(5)e_(g)^(2))owing to asymmetric coordination.The high-spin Co 3d orbital in CoN_(1)C_(2)/C_(2)N possessed more unpaired electrons and therefore,had a strong ability to gain electrons from the O 2p orbitals of HSO_(5)^(–),boosting d-p orbital hybridization.More importantly,the spin-electron filling in theσ^(*)orbital of high-spin Co 3d−O 2p accelerated the desorption of^(*)SO_(5)•^(−),which acted as a rate-limiting step in the reaction,thus facilitating more^(1)O_(2)generation.This study provides an innovative synthetic route for practical ASACs and clarifies the critical relationship between structure and spin state,paving the way for advancements in environmental remediation and energy conversion applications.
基金financially supported by the National Natural Science Foundation of China(No.22375019)Beijing Institute of Technology Research Fund Program for Young Scholars(No.3090012221909)
文摘CO_(2)electroreduction(CO_(2)RR)represents a promising negative-carbon technology,which is in urgent need for efficient and high-selectivity catalysts.Here,a support control strategy is employed for precise surface engineering of charge-asymmetry nanocluster catalyst(CuZnSCN),in which zinc and copper atoms together form a metal cluster loaded on sulfur and nitrogen co-etched carbon matrix.The synergistic promotion mechanism of CO_(2)RR by Cu–Zn atom interactions and sulfur–nitrogen atom doping was investigated.A CO partial current density of 74.1 mA cm^(-2)was achieved in an alkaline electrolyte,as well as a considerable CO Faraday efficiency of 97.7%.In situ XAS(X-ray absorption spectroscopy)showed that the stabilization of Cu^(+)and Zn^(2+)species in the nanoclusters and doped sulfur atoms during the CO_(2)RR process contributes to the sustained adsorption of protons and the generation and conversion of the CO.This work verifies the possibility of metal-support and intermetallic interactions to synergistically enhance electrochemical catalytic performance and provides ideas for further bimetallic cluster catalyst development.
基金supported by the Research Grants Council(16310419,16309418,and 16304821)the Innovation and Technology Commission(Grant No.ITC-CNERC14EG03)of the Hong Kong Special Administrative Region+4 种基金the Hong Kong Branch of National Precious Metals Material Engineering Research Centre,City University of Hong Kongthe Strategic Hiring Scheme of The Hong Kong Polytechnic University(P0047728)GuangDong Basic and Applied Basic Research Foundation(2023A1515110259)National Natural Science Foundation of China(22405228)Guangzhou Science and Technology Bureau(2024A03J0609)。
文摘Cu-based metal-organic frameworks(Cu-MOFs)electrocatalysts are promising for CO_(2)reduction reactions(CO_(2)RR)to produce valuable C_(2+)products.However,designing suitable active sites in Cu-MOFs remains challenging due to their inherent structural instability during CO_(2)RR.Here we propose a synergistic strategy through thermal annealing and electrochemicalactivation process for in-situ reconstruction of the pre-designed Cu-MOFs to produce abundant partially oxidized Cu(Cu^(δ+))active species.The optimized MOF-derived Cu^(δ+)electrocatalyst demonstrates a highly selective production of C_(2+)products,with the Faradaic Efficiency(FE)of 78±2%and a partial current density of-46 m A cm-2at-1.06 VRHEin a standard H-type cell.Our findings reveal that the optimized Cu^(δ+)-rich surface remains stable during electrolysis and enhances surface charge transfer,leading to an increase in the concentration of*CO intermediates,thereby highly selectively producing C_(2+)compounds.This study advances the controllable formation of MOF-derived Cu^(δ+)-rich surfaces and strengthens the understanding of their catalytic role in CO_(2)RR for C_(2+)products.
基金This work was supported by the Beijing Natural Science Foundation(No.2212018)the National Natural Science Foundation of China(No.22105116)+2 种基金Natural Science Foundation of Hebei Province(No.B2021208001)Key Research and Development Program of Shijiazhuang(No.221070361A)the Beijing Institute of Technology Research Fund Program for Young Scholars。
文摘Single atom catalysts(SACs)have attracted great attention,yet the quest for highly-efficient catalysts is driven by the current obstacles of ambiguous structure-performance relationship.Here,we report a nature keratin-based Fe-S_(1)N_(3)SACs with ultrathin two-dimensional(2D)porous carbon nanosheets structure,by controlling the active center through the precise coordination of sulfur and nitrogen.Compared with natural silk-based Fe-N_(4) catalyst,the Fe-S_(1)N_(3)SACs exhibit excellent Fenton-like oxidation degradation ability.X-ray absorption fine structure(XAFS)and electron paramagnetic resonance(EPR)results confirm that S doping is conducive to electron transfer,to accurately generate·OH with high oxidative degradation capacity at the active site.Therefore,the optimized Fe-S_(1)N_(3)catalyst showed higher oxidation degradation activity for organic pollutant substrates(methylene blue(MB),Rhodamine B(RhB)and phenol),significantly superior to Fe-N_(4) samples.This work is devoted to the treatment and application of natural fibers,which provides a novel method for the synthesis of SACs and the regulation of atomic coordination environment.
基金financially supported by the National Natural Science Foundation of China(Nos.U180413,11904084,and U2004212)Center for Outstanding Overseas Scientists(No.GZS2023007).
文摘Molecular catalysts with well-defined single atom sites and coordination environments exhibit significant potential as oxygen reduction electrocatalysts,but suffering from the activity and stability issues.Herein,the ultrathin carbon shell supported FePc molecule electrocatalysts(FePc/TA-ONG-N),featuring with a direct oxygen bridging between FePc and carbon substrate,were designed and synthesized.The direct connection with oxygen atom on carbon substrate,certified by the Fourier transform infrared spectroscopy(FTIR)and extended X-ray absorption fine structure(EXAFS),can remarkably enhance the interaction and facilitate electron transfer from Fe,leading to an improved activity by reducing adsorption strength of intermediate species through lowering the d-band center position.The resultant half-wave potential of 0.902 V together with a Tafel slope of 23.64 mV·dec^(−1)is superior to Pt/C and control samples.Such catalyst holds a promise as air-cathode electrocatalyst in Zn-air battery with excellent operation stability exceeding 80 h.The density functional theory(DFT)calculations and molecular dynamic simulations unveiled that the O-bridge can effectively stabilize the FePc molecule and function as electron buffer to donate/gain electrons to/from Fe atom during the adsorption of oxygenates.The current findings are insightful for developing molecular catalysts with high performance through substrate engineering and axial coordination.
基金supported by the National Natural Science Foundation of China(NSFC),Basic Sciences Center Program(Extreme Light Field Manufacturing,No.52488301)and NSFC General Program(No.52475425)the National Key R&D Program of China(No.2022YFB4601300)Aeronautical Science Fund(No.3030021252404).
文摘Elucidation of a physicochemical process on nanocatalysts,especially under continuously evolving conditions,is often heavily tool-driven because of technical challenges.Recently,ambient pressure X-ray photoelectron spectroscopy(APXPS)emerges as an emerging photon-in-electron-out technique in in-situ/operando analysis by bridging the pressure-gap between conventional ultra-high vacuum(UHV)and near ambient or even close to operating conditions,rendering the advancement of XPS from a UHV-based technique to a versatile and powerful tool that enables the specific probe of numerous events taking place at the gas–solid,liquid–solid and liquid–gas nanoscale interfaces which are critical to nanocatalysis research.For example,APXPS probes information on catalytically active phase and reaction kinetics in nanocatalytic processes;details inside the electric double-layer at an electrolyte/electrode interface can now be accessed;more efficient nanocatalyst design can be achieved and energy transfer venues can be optimized.Here,we aim to critically review the recent advances in instrumentation and the probe of the gas–solid,liquid–solid,and gas–liquid nanoscale interfaces using APXPS-based methodologies,followed by putting forward an outlook of development of APXPS as a rising in-situ/operando analytical means in surface science,nanocatalysis,nanoscience materials science.
基金supported by the National Natural Science Foundation of China(No.22201262).
文摘By incorporating a limited number of precious metal atoms into the base metal,the single-atom alloy catalyst not only optimizes the electronic structure and stability of the catalyst but also emerges as an innovative material that enhances the efficiency and selectivity of catalytic reactions.RuCo single-atom alloy electrocatalyst supported on S,N co-doped carbon nanosheets(RuCo SAA/SNC)uniformly distributed on nitrogen,sulfur co-doped carbon nanosheets was prepared by two-step pyrolysis and carbonization.The incorporation of Ru not only optimizes the atomic utilization of Ru but also enhances the charge conduction properties of the surface Co species,thereby increasing the evolution and migration rates of hydrogen ions.In a 0.5 M H_(2)SO_(4) solution,the RuCo SAA/SNC catalyst demonstrates a tafel slope of 27.5 mV·dec^(-1) and an overpotential of merely 43 mV at 10 mA·cm^(-2).This work achieves enhanced catalytic performance and stability by precisely regulating the atomic-level structure of single-atom alloy catalysts,thereby promoting their widespread application in energy conversion and green chemistry.
基金supported by the National Natural Science Foundation of China(No.22375019)Postdoctoral Fellowship Program of CPSF under Grant Number GZC20252673.
文摘The electrocatalytic C-N coupling reaction as a green synthesis approach for C-N bond synthesis via electrochemical processes with catalytic assistance.However,inefficient reactant adsorption onto the catalyst surface,competing side reactions,and the complexity and diversity of reaction pathways hinder its widespread application.Atomically dispersed catalysts(ADCs),as an emerging class of catalytic materials,possess precisely defined active sites,high catalytic activity,and enhanced selectivity,thereby enabling efficient electrocatalytic C-N coupling to address these challenges.This review discusses current reaction pathways for converting small molecules(CO_(2)as the carbon source,N_(2),NO_(2)^(-),NO_(3)^(-)as the nitrogen source)into high-value organic nitrogen compounds(urea,amides,oximes,and amino acids)utilizing ADCs.It specifically focuses on the critical steps within electrocatalytic C-N coupling facilitated by these catalysts,encompassing reactant adsorption,transformation and selective hydrogenation of C-/N-intermediates,and the C-N coupling reaction itself.Based on these key steps,design principles for ADCs are proposed.Finally,the synthesis strategies for ADCs-vacancy engineering,confinement strategies,and alloying-are examined,alongside the mechanisms by which they enhance catalytic activity and selectivity.
基金The authors thank the National Natural Science Foundation of China(No.U1804140)China Postdoctoral Science Foundation(No.2021M702939)for support.
文摘Transition metal sulfides with homogeneous multi-metallic elements promise high catalytic performance for water electrolysis owing to the unique structure and highly tailorable electrochemical property.Most existing synthetic routes require high temperature to ensure the uniform mixing of various elements,making the synthesis highly challenging.Here,for the first-time novel carbon fiber supported high-entropy Co-Zn-Cd-Cu-Mn sulfide(CoZnCdCuMnS@CF)nanoarrays are fabricated by the mild cation exchange strategy.Benefiting from the synergistic effect among multiple metals and the strong interfacial bonding between high-entropy Co-Zn-Cd-Cu-Mn sulfide nanoarrays and the carbon fiber support,CoZnCdCuMnS@CF exhibits superior catalytic activity and stability toward overall water splitting in alkaline medium.Impressively,CoZnCdCuMnS@CF only needs low overpotentials of 173 and 220 mV to reach the current density of 10 mA•cm^(−2),with excellent durability for over 70 and 113 h for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)respectively.More importantly,the bifunctional electrode(CoZnCdCuMnS@CF||CoZnCdCuMnS@CF)for overall water splitting can deliver a small cell voltage of 1.63 V to afford 10 mA•cm^(−2) and exhibit outstanding stability of negligible decay after 73 h continuous operation.This work provides a viable synthesis route toward advanced high-entropy materials with great potential applications.
基金This work was supported by the National Natural Science Foundation of China(No.21801015)Beijing Institute of Technology Research Fund Program for Young Scholars.
文摘The depletion of energy and increasing environmental pressure have become one of the main challenges in the world today.Synthetic high-efficiency catalysts bring hope for efficient conversion of energy and effective treatment of pollutants,especially,single-atom catalysts(SACs)are promising candidates.Herein,we comprehensively summarizes the atomic diffusion strategy,which is considered as an effective method to prepare a series of SACs.According to the different diffusion forms of the precursors,we review the synthesis pathways of SACs from three aspects:gas diffusion,solid diffusion and liquid diffusion.The gaseous diffusion method mainly discusses atomic layer deposition(ALD)and chemical vapor deposition(CVD),both of which carry out gas phase mass transfer at high temperatures.The solid-state diffusion method can be divided into nanoparticle transformation into single atoms and solid atom migration.Liquid diffusion mainly describes the electrochemical method and the molten salt method.We hope this review can trigger the rational design of SACs.
基金supported by the National Natural Science Foundation of China(No.22074095)Beijing Municipal Natural Science Foundation(No.2222005)High-level Teachers in Beijing Municipal Universities in the Period of 13th Five-Year Plan(No.CIT&TCD20190330).
文摘Although nanozyme has become an emerging area of research attracting extensive attention recently,the activity and specificity of currently reported nanozymes are generally lower than those of natural enzymes.Developing highly active and specific nanozymes is therefore extremely necessary and also remains a great challenge.Superoxide dismutase(SOD)catalyzes the disproportionation of cytotoxic O_(2)·^(−)into hydrogen peroxide and oxygen,and plays an important role in reducing human oxidative stress.In this work,we prepare Cu single-atom catalysts(Cu/GO SACs,GO=graphene oxide)through a simple and low-cost strategy at room temperature using Cu foam and graphene oxide.Cu/GO SACs can maintain excellent catalytic activity under harsh environment.Compared with the natural enzyme,SOD-like Cu/GO SAC nanozyme has higher catalytic activity and meanwhile,it does not possess the common properties of other mimic enzymes often existing in nanomaterials.Based on the excellent SOD-like enzyme activity of Cu/GO SACs,it successfully eliminates the active oxygen in cigarette smoke.This work not only provides a new idea for the design and synthesis of nanozymes with excellent SOD mimetic properties,but also is promising in the treatment of lung injury and inflammatory diseases related to free radical production.
基金The authors thank the National Natural Science Foundation of China(Nos.U1804140,U20041100 and 21801015)for supportThis work is also supported by Beijing Institute of Technology Research Fund Program for Young Scholars(No.3090012221909).
文摘Rational design and construction of low-cost and highly efficient electrocatalysts for hydrogen evolution reaction(HER)is meaningful but challenging.Herein,a robust three dimensional(3D)hollow CoSe_(2)@ultrathin MoSe_(2)core@shell heterostructure(CoSe_(2)@MoSe_(2))is proposed as an efficient HER electrocatalyst through interfacial engineering.Benefitting from the abundant heterogeneous interfaces on CoSe_(2)@MoSe_(2),the exposed edge active sites are maximized and the charge transfer at the hetero-interfaces is accelerated,thus facilitating the HER kinetics.It exhibits remarkable performance in pH-universal conditions.Notably,it only needs an overpotential(η10)of 108 mV to reach a current density of 10 mA·cm^(-2)in 1.0 M KOH,outperforming most of the reported transition metal selenides electrocatalysts.Density functional theory(DFT)calculations unveil that the heterointerfaces synergistically optimize the Gibbs free energies of H2O and H^(*)during alkaline HER,accelerating the reaction kinetics.The present work may provide new construction guidance for rational design of high-efficient electrocatalysts.
基金supported by the Beijing Natural Science Foundation(No.2212018)China National Petroleum Corporation(CNPC)Innovation Found(No.2021DQ02-0202)the National Natural Science Foundation of China(No.51902013).
文摘The atomic-level interfacial regulation of single metal sites through heteroatom doping can significantly improve the characteristics of the catalyst and obtain surprising activity.Herein,nickel single-site catalysts(SSCs)with dual-coordinated phosphorus and nitrogen atoms were developed and confirmed(denoted as Ni-PxNy,x=1,2 and y=3,2).In CO_(2)reduction reaction(CO_(2)RR),the CO current density on Ni-PxNy was significantly higher than that of Ni-N4 catalyst without phosphorus modification.Besides,Ni-P1N3 performed the highest CO Faradaic efficiency(FECO)of 85.0%–98.0%over a wide potential range of−0.65 to−0.95 V(vs.the reversible hydrogen electrode(RHE)).Experimental and theoretical results revealed that the asymmetric Ni-P1N3 site was beneficial to CO_(2)intermediate adsorption/desorption,thereby accelerating the reaction kinetics and boosting CO_(2)RR activity.This work provides an effective method for preparing well-defined dual-coordinated SSCs to improve catalytic performance,targetting to CO_(2)RR applications.
基金supported by the Special Program on the Promotion of Graduate Research Level and Innovation Ability of Beijing Institute of Technology 2022(No.2022YCXZ003).
文摘Producing hydrogen peroxide(H_(2)O_(2))through an electrochemical oxygen reduction reaction(ORR)is a safe,green strategy and a promising alternative to traditional energy-intensive anthraquinone processes.Air and renewable power could be utilized for onsite and decentralized H_(2)O_(2)production,demonstrating significant application potential.Currently,single atom catalysts(SACs)have demonstrated significant advantages in the catalytic production of H_(2)O_(2)in 2e−ORR.However,the selectivity of SACs in ORR once puzzled researchers.This article reviews the research on the development and achievements of H_(2)O_(2)production by SACs catalysis in recent years.Especially,the structure-performance relationship is a guide to designing new SACs.Combining advanced characterization techniques and theoretical calculation methods,researchers have a clearer and more thorough understanding of the impact of the atomic interface of SACs on ORR catalytic performance.The coordination moiety formed between the active metal center atom and the support seriously determines the selectivity of SACs,mainly manifested in the adsorption of*OOH intermediates.Particularly,the atomic interface of metal atoms together with O/N co-coordination exhibit high selectivity and mass activity,and heteroatoms or functional groups on carbon supports present synergistic effects to promote the production of H_(2)O_(2)in 2e−ORR.Fine and accurate regulation of the atomic interface of SACs directly affects the 2e−ORR performance of the catalysts.Therefore,it is important to deeply understand the atomic interface of SACs and contribute to the development of novel catalysts.
基金supported by the National Natural Science Foundation of China(22375019)Beijing Natural Science Foundation(Grant No.2212018)Beijing Institute of Technology Research Fund Program for Young Scholars(2022CX01011).
文摘Energy transformation is imminent,and hydrogen energy is one of the important new energy sources.One of the keys to increasing the rate of hydrogen evolution during electrolysis is the use of high-performance catalysts for oxygen evolution reactions(OER).Single-atom alloys(SAAs)have garnered significant attention because they partially reduce costs and combine the advantages of both single-atom catalysts(SACs)and alloy catalysts.Herein,an efficient pyrolysis strategy based on a mixing and drying process is designed to anchor ultra-small Co cluster particles,combined with Ru single atoms dispersed on nitrogen-doped ultra-thin carbon nanosheets(Ru_(1)Co SAA/NC).The prepared electrocatalyst exhibits superior OER activity and superb stability,demonstrating an overpotential of 238 mV for OER with a current density of 10 mA·cm^(-2) in 0.5 mol/L H_(2)SO_(4).And we also utilized in-situ XAS to detect the oxidation state of Ru sites during OER.All in all,this method achieves cost reductions and efficiency improvements through the design of SAAs,offering new prospects for the structural transformation of clean energy.
基金supported by the National Natural Science Foundation of China(Nos.22201262 and 51902013)Natural Science Foundation of Henan Province(No.222300420290)+1 种基金Foundation of Department of Science and Technology of Guizhou province(No.[2019]1297)Engineering Research Center of Guihzou province(No.[2018]487).
文摘Developing cost-effective and high-efficiency oxygen reduction reaction(ORR)catalysts is imperative for promoting the substantial progress of fuel cells and metal-air batteries.The coordination and geometric engineering of single-atom catalysts(SACs)occurred the promising approach to overcome the thermodynamics and kinetics problems in high-efficiency electrocatalysis.Herein,we rationally constructed atomically dispersed Co atoms on porous N-enriched graphene material C_(2)N(CoSA-C2N)for efficient oxygen reduction reaction(ORR).Systematic characterizations demonstrated the active sites for CoSA-C2N is as identified as coordinatively unsaturated Co-N_(2)moiety,which exhibits ORR intrinsic activity.Structurally,the porous N-enriched graphene framework in C_(2)N could effectively increase the accessibility to the active sites and promote mass transfer rate,contributing to improved ORR kinetics.Consequently,CoSA-C_(2)N exhibited superior ORR performance in both acidic and alkaline conditions as well as impressive long-term durability.The coordination and geometric engineering of SACs will provide a novel approach to advanced catalysts for energy related applications.
基金This work was supported by the National Natural Science Foundation of China(Nos.51872011,51902011,and 22005013)The authors thank the BL14W1 in the Shanghai Synchrotron Radiation Facility(SSRF),BL10B and BL12B in the National Synchrotron Radiation Laboratory(NSRL)for help with characterizations.
文摘Interface regulation plays a key role in the electrochemical performance for biosensors.By controlling the interfacial interaction,the electronic structure of active species can be adjusted effectively at micro and nano-level,which results in the optimal reaction energy barrier.Herein,we propose an interface electronic engineering scheme to design a strongly coupled 1T phase molybdenum sulfide(1T-MoS2)/MXene hybrids for constructing an efficient electrocatalytic biomimetic sensor.The local electronic and atomic structures of the 1T-MoS2/Ti3C2TX are comprehensively studied by synchrotron radiation-based X-ray photoelectron spectroscopy(XPS),as well as X-ray absorption spectroscopy(XAS)at atomic level.Experiments and theoretical calculations show that there are interfacial stresses,atomic defects and adjustable bond-length between MoS2/MXene nanosheets,which can significantly promote biomolecular adsorption and rapid electron transfer to achieve excellent electrochemical activity and reaction kinetics.The 1T-MoS2/Ti3C2TX modified electrode shows ultra high sensitivity of 1.198μA/μM for dopamine detection with low limit of 0.05μM.We anticipate that the interface electronic engineering investigation could provide a basic idea for guiding the exploration of advanced biosensors with high sensitivity and low detection limit.
基金This work was funded by the Shandong Province Major Scientific and Technological Innovation Project(No.2021CXGC010803)the National Natural Science Foundation of China(No.21876188)+1 种基金M.Y.acknowledges National Research Foundation Competitive Research Programs(No.NRFCRP24-2020-0002)M.Y.acknowledges the funding support(project ID:1-BE47,ZE0C,ZE2F,and ZE2X)from the Hong Kong Polytechnic University.We acknowledge the Centre for Advanced 2D Materials and Graphene Research at the National University of Singapore and the National Supercomputing Centre Singapore for providing computing resources.
文摘Exploiting inexpensive and effective nickel-based catalysts that produce hydrogen from liquid organic hydrogen carriers(LOHCs)is crucial to alleviating the global energy and environmental crisis.In this study,we report a rational strategy that can realize atomically dispersed Ni atoms anchored on vacancy-abundant boron nitride nanosheets(Ni1/h-BNNS)with high specific surface area(up to 622 m^(2)·g^(-1))and abundant hydroxyl groups for high efficient hydrogen production.Methanol dehydrogenation results show an excellent hydrogen production performance catalyzed by this Ni1/h-BNNS,as evidenced by a remarkably high H_(2) yield rate(1684.23 mol·mol_(Ni)^(-1)·h^(-1)),nearly 100%selectivity toward hydrogen and CO,and high anti-coking performance.Density functional theory(DFT)calculations reveal that the outstanding catalytic performance of Ni1/h-BNNS primarily originates from the unique coordinated environment of atomically dispersed Ni(Ni-B_(2)O_(2))and the synergistic interaction between Ni single atoms and the h-BNNS support.Specifically,the coordinated O atoms play a decisive role in promoting the activity of Ni,and the neighboring B sites significantly decrease the energy barriers for the adsorption of key intermediates of methanol dehydrogenation.This study offers a novel strategy for developing high-performance and stable single-atom Ni catalysts by precisely controlling single-atom sites on h-BN support for sustainable hydrogen production.
