Electrocatalytic nitric oxide(NO)reduction reaction(NORR)is a promising and sustainable process that can simultaneously realize green ammonia(NH3)synthesis and hazardous NO removal.However,current NORR performances ar...Electrocatalytic nitric oxide(NO)reduction reaction(NORR)is a promising and sustainable process that can simultaneously realize green ammonia(NH3)synthesis and hazardous NO removal.However,current NORR performances are far from practical needs due to the lack of efficient electrocatalysts.Engineering the lattice of metal-based nanomaterials via phase control has emerged as an effective strategy to modulate their intrinsic electrocatalytic properties.Herein,we realize boron(B)-insertion-induced phase regulation of rhodium(Rh)nanocrystals to obtain amorphous Rh_(4)B nanoparticles(NPs)and hexagonal close-packed(hcp)RhB NPs through a facile wet-chemical method.A high Faradaic efficiency(92.1±1.2%)and NH_(3) yield rate(629.5±11.0μmol h^(−1) cm^(−2))are achieved over hcp RhB NPs,far superior to those of most reported NORR nanocatalysts.In situ spectro-electrochemical analysis and density functional theory simulations reveal that the excellent electrocatalytic performances of hcp RhB NPs are attributed to the upshift of d-band center,enhanced NO adsorption/activation profile,and greatly reduced energy barrier of the rate-determining step.A demonstrative Zn-NO battery is assembled using hcp RhB NPs as the cathode and delivers a peak power density of 4.33 mW cm−2,realizing simultaneous NO removal,NH3 synthesis,and electricity output.展开更多
Proton-exchange membrane fuel cell and water electrolyzer(PEMFC and PEMWE)with high conversion efficiency and zero-carbon emission stand out as an attractive strategy for efficient conversion between hydrogen energy a...Proton-exchange membrane fuel cell and water electrolyzer(PEMFC and PEMWE)with high conversion efficiency and zero-carbon emission stand out as an attractive strategy for efficient conversion between hydrogen energy and renewable electricity.As a key component,efficient oxygen electrocatalyst for promoting sluggish reaction kinetics of oxygen reduction and evolution reaction(ORR and OER)under harsh operation conditions severely limited progress of these devices.Among various candidates,Ptgroup(Pt,Ir,and Ru)-based electrocatalysts are still the most active ORR/OER catalysts.However,the scarcity,high cost,and questionable stability restrict the widespread applications and the commercialization of PEMWE/PEMFC.Progresses in synthesizing atomically dispersed single/multiple-atom catalysts(SACs/MACs)offer new opportunities to Pt-group ORR/OER catalysts owing to nearly 100% metal utilization and high catalytic activities.Extensive efforts have been continuously devoted to optimizing the local structure of Pt-group OER/ORR catalysts at atom-level for further enhancing stability and activity.In this review,universal synthesis methods to prepare Ptgroup SACs are discussed first,highlighting crucial factors which affect the structure and catalytic performance.Afterward,advanced characterization techniques for directly confirming atomic dispersed metal atoms were introduced,including aberration-corrected high-angle-annular-dark-field scanning transmission electron microscopy and X-ray absorption spectroscopy.Importantly,considerations for rational catalyst design and typical Pt-group SACs/MACs are summarized regarding the regulation strategy of atomically dispersed metal sites and various supports,and effects of metal-support interaction on the catalytic performance.Finally,key challenges and proposed perspectives for future development of atomically dispersed Pt-group oxygen electrocatalysts for fuel cell and electrolyzer are briefly discussed.展开更多
The coupling of photoanode(Pho)and oxygen evolution catalyst(OEC)is an ideal approach to enhance the photoelectrochemical(PEC)activity.Nevertheless,the anticipated photocurrent density has not been reached due to slow...The coupling of photoanode(Pho)and oxygen evolution catalyst(OEC)is an ideal approach to enhance the photoelectrochemical(PEC)activity.Nevertheless,the anticipated photocurrent density has not been reached due to slow charge transfer dynamics and severe charge recombination at the interface.Herein,a novel“killing two birds with one stone”approach was discovered by employing CoPi as an interface mediator,which shifts its charge transfer behavior from conventional hole storage or passivation to hole transporter.The optimized BiVO_(4)/CoPi/FeOOH photoanode achieves a noteworthy photocurrent density of 5.4 mA/cm^(2) and exhibits long term stability(13 h).The dynamic analysis and electrochemical characterization reveal that CoPi can rapidly and directly transfer more photogenerated holes to the surface of OEC in comparison to traditional slow holes transfer behavior,resulting in highly efficient interface charge separation.Interestingly,the strong interfacial interactions can also be extended to OEC/electrolyte interface,specifically by promoting the surface reaction dynamics.Moreover,this innovative approach of altering behavior of CoPi can also be utilized to design other photoanodes,like BiVO_(4)/CoPi/NiOOH,aimed at efficient PEC water splitting.This finding affords a smart strategy to develop highly efficient and stable photoelectrodes for water splitting.展开更多
Single-atom catalysts based on graphitic carbon nitride(g-C_(3)N_(4))show high potential for hydrogen production photocatalytically.However,it is still a challenge to develop single-atom-based g-C_(3)N_(4)due to the c...Single-atom catalysts based on graphitic carbon nitride(g-C_(3)N_(4))show high potential for hydrogen production photocatalytically.However,it is still a challenge to develop single-atom-based g-C_(3)N_(4)due to the complex synthesis procedures,limited active sites,and insufficient mechanistic understanding.Herein,a facile oxygen-tolerant synthesis strategy was developed,which utilizes the nitrogen-rich structure of g-C_(3)N_(4)to capture Fe single atoms from ammonium iron citrate,successfully constructing an efficient photocatalytic composite.The resulting Fe single-atom-modified g-C_(3)N_(4)catalyst exhibited highly improved light absorption,charge carrier separation,and a substantially enhanced rate of H_(2)production photocatalytically under visible light irradiation.Experimental results demonstrated that the optimal sample achieves a H_(2)production rate of 683μmol·h-1·g^(-1),representing a 425% enhancement compared to pristine g-C_(3)N_(4).This study presents a facile oxygen-tolerant approach for metal immobilization using metal-organic precursors,where the nitrogen-rich framework of g-C_(3)N_(4)effectively captures Fe atoms as singular site within the composite.The developed synthesis strategy provides new insights for designing high-performance single-atom photocatalytic materials,potentially advancing the application and development of photocatalysis.展开更多
The transition to sustainable energy systems necessitates efficient hydrogen production via water electrolysis,with anion-exchange membrane water electrolyzers(AEMWEs)emerging as a cost-effective alternative by combin...The transition to sustainable energy systems necessitates efficient hydrogen production via water electrolysis,with anion-exchange membrane water electrolyzers(AEMWEs)emerging as a cost-effective alternative by combining the merits of alkaline water electrolyzers(AWEs)and proton-exchange membrane water electrolyzers(PEMWEs).However,challenges persist in membrane stability,oxygen evolution reaction(OER)kinetics,and mass transport efficiency.This review highlights the pivotal role of transition metal-based layered double hydroxides(LDHs)as high-performance,non-precious OER catalysts for AEMWEs,emphasizing their tunable electronic structures,abundant active sites,and alkaline stability.We systematically outline LDHs synthesis strategies(top-down/bottom-up approaches,and self-supporting LDHs engineering on the conductive substrates),and AEMWE component design,including membraneelectrode assembly optimization and ionomer-free architectures.Standardized evaluation protocols-short-circuit inspection,impedance spectroscopy,and durability assessment are detailed to benchmark performance.Moreover,recent advances in LDHs modification(cation/anion doping,heterojunction design,three-dimensional(3D)electrode structuring)are discussed for alkaline-fed systems,alongside emerging applications in seawater and pure-water electrolysis.By correlating material innovations with device-level metrics,this work provides a roadmap to address scalability challenges,offering perspectives on advancing AEMWEs for sustainable,large-scale hydrogen production.展开更多
基金funding support from General Research Fund[Project No.14300525]from the Research Grants Council(RGC)of Hong Kong SAR,Chinafunding support from Natural Science Foundation of China(NSFC)Young Scientists Fund(Project No.22305203)+2 种基金NSFC Projects Nos.22309123,22422303,22303011,22033002,92261112 and U21A20328support from the Hong Kong Branch of National Precious Metals Material Engineering Research Center(NPMM)at City University of Hong Kongsupport from Young Collaborative Research Grant[Project No.C1003-23Y]support from RGC of Hong Kong SAR,China.
文摘Electrocatalytic nitric oxide(NO)reduction reaction(NORR)is a promising and sustainable process that can simultaneously realize green ammonia(NH3)synthesis and hazardous NO removal.However,current NORR performances are far from practical needs due to the lack of efficient electrocatalysts.Engineering the lattice of metal-based nanomaterials via phase control has emerged as an effective strategy to modulate their intrinsic electrocatalytic properties.Herein,we realize boron(B)-insertion-induced phase regulation of rhodium(Rh)nanocrystals to obtain amorphous Rh_(4)B nanoparticles(NPs)and hexagonal close-packed(hcp)RhB NPs through a facile wet-chemical method.A high Faradaic efficiency(92.1±1.2%)and NH_(3) yield rate(629.5±11.0μmol h^(−1) cm^(−2))are achieved over hcp RhB NPs,far superior to those of most reported NORR nanocatalysts.In situ spectro-electrochemical analysis and density functional theory simulations reveal that the excellent electrocatalytic performances of hcp RhB NPs are attributed to the upshift of d-band center,enhanced NO adsorption/activation profile,and greatly reduced energy barrier of the rate-determining step.A demonstrative Zn-NO battery is assembled using hcp RhB NPs as the cathode and delivers a peak power density of 4.33 mW cm−2,realizing simultaneous NO removal,NH3 synthesis,and electricity output.
基金supported by the National Key Research and Development Program of China(No.2021YFB4000603)the National Natural Science Foundation of China(Nos.52273277 and U24A2062)+2 种基金Jilin Province Science and Technology Development Plan Funding Project(No.SKL202302039)Youth Innovation Promotion Association CAS(No.2021223)funding from National Natural Science Foundation of China Outstanding Youth Science Foundation of China(Overseas).
文摘Proton-exchange membrane fuel cell and water electrolyzer(PEMFC and PEMWE)with high conversion efficiency and zero-carbon emission stand out as an attractive strategy for efficient conversion between hydrogen energy and renewable electricity.As a key component,efficient oxygen electrocatalyst for promoting sluggish reaction kinetics of oxygen reduction and evolution reaction(ORR and OER)under harsh operation conditions severely limited progress of these devices.Among various candidates,Ptgroup(Pt,Ir,and Ru)-based electrocatalysts are still the most active ORR/OER catalysts.However,the scarcity,high cost,and questionable stability restrict the widespread applications and the commercialization of PEMWE/PEMFC.Progresses in synthesizing atomically dispersed single/multiple-atom catalysts(SACs/MACs)offer new opportunities to Pt-group ORR/OER catalysts owing to nearly 100% metal utilization and high catalytic activities.Extensive efforts have been continuously devoted to optimizing the local structure of Pt-group OER/ORR catalysts at atom-level for further enhancing stability and activity.In this review,universal synthesis methods to prepare Ptgroup SACs are discussed first,highlighting crucial factors which affect the structure and catalytic performance.Afterward,advanced characterization techniques for directly confirming atomic dispersed metal atoms were introduced,including aberration-corrected high-angle-annular-dark-field scanning transmission electron microscopy and X-ray absorption spectroscopy.Importantly,considerations for rational catalyst design and typical Pt-group SACs/MACs are summarized regarding the regulation strategy of atomically dispersed metal sites and various supports,and effects of metal-support interaction on the catalytic performance.Finally,key challenges and proposed perspectives for future development of atomically dispersed Pt-group oxygen electrocatalysts for fuel cell and electrolyzer are briefly discussed.
基金the National Natural Science Foundation of China(Nos.22202126,52273186,51873100,and 62105194)San Qin Scholars Innovation Teams in Shaanxi Province,China,International Joint Research Center of Shaanxi Province for Photoelectric Materials Science,and International Science and Technology Cooperation Project of Shaanxi Province,China(No.2021KW-20).
文摘The coupling of photoanode(Pho)and oxygen evolution catalyst(OEC)is an ideal approach to enhance the photoelectrochemical(PEC)activity.Nevertheless,the anticipated photocurrent density has not been reached due to slow charge transfer dynamics and severe charge recombination at the interface.Herein,a novel“killing two birds with one stone”approach was discovered by employing CoPi as an interface mediator,which shifts its charge transfer behavior from conventional hole storage or passivation to hole transporter.The optimized BiVO_(4)/CoPi/FeOOH photoanode achieves a noteworthy photocurrent density of 5.4 mA/cm^(2) and exhibits long term stability(13 h).The dynamic analysis and electrochemical characterization reveal that CoPi can rapidly and directly transfer more photogenerated holes to the surface of OEC in comparison to traditional slow holes transfer behavior,resulting in highly efficient interface charge separation.Interestingly,the strong interfacial interactions can also be extended to OEC/electrolyte interface,specifically by promoting the surface reaction dynamics.Moreover,this innovative approach of altering behavior of CoPi can also be utilized to design other photoanodes,like BiVO_(4)/CoPi/NiOOH,aimed at efficient PEC water splitting.This finding affords a smart strategy to develop highly efficient and stable photoelectrodes for water splitting.
基金financially supported by the National Natural Science Foundation of China(No.22272159)the Chinese Academy of Sciences(No.KFJ-XCZX-202304).
文摘Single-atom catalysts based on graphitic carbon nitride(g-C_(3)N_(4))show high potential for hydrogen production photocatalytically.However,it is still a challenge to develop single-atom-based g-C_(3)N_(4)due to the complex synthesis procedures,limited active sites,and insufficient mechanistic understanding.Herein,a facile oxygen-tolerant synthesis strategy was developed,which utilizes the nitrogen-rich structure of g-C_(3)N_(4)to capture Fe single atoms from ammonium iron citrate,successfully constructing an efficient photocatalytic composite.The resulting Fe single-atom-modified g-C_(3)N_(4)catalyst exhibited highly improved light absorption,charge carrier separation,and a substantially enhanced rate of H_(2)production photocatalytically under visible light irradiation.Experimental results demonstrated that the optimal sample achieves a H_(2)production rate of 683μmol·h-1·g^(-1),representing a 425% enhancement compared to pristine g-C_(3)N_(4).This study presents a facile oxygen-tolerant approach for metal immobilization using metal-organic precursors,where the nitrogen-rich framework of g-C_(3)N_(4)effectively captures Fe atoms as singular site within the composite.The developed synthesis strategy provides new insights for designing high-performance single-atom photocatalytic materials,potentially advancing the application and development of photocatalysis.
基金supported by the National Natural Science Foundation of China(Nos.52122308 and 22305225)the Postdoctoral Fellowship Program of CPSF(No.GZC20232391).
文摘The transition to sustainable energy systems necessitates efficient hydrogen production via water electrolysis,with anion-exchange membrane water electrolyzers(AEMWEs)emerging as a cost-effective alternative by combining the merits of alkaline water electrolyzers(AWEs)and proton-exchange membrane water electrolyzers(PEMWEs).However,challenges persist in membrane stability,oxygen evolution reaction(OER)kinetics,and mass transport efficiency.This review highlights the pivotal role of transition metal-based layered double hydroxides(LDHs)as high-performance,non-precious OER catalysts for AEMWEs,emphasizing their tunable electronic structures,abundant active sites,and alkaline stability.We systematically outline LDHs synthesis strategies(top-down/bottom-up approaches,and self-supporting LDHs engineering on the conductive substrates),and AEMWE component design,including membraneelectrode assembly optimization and ionomer-free architectures.Standardized evaluation protocols-short-circuit inspection,impedance spectroscopy,and durability assessment are detailed to benchmark performance.Moreover,recent advances in LDHs modification(cation/anion doping,heterojunction design,three-dimensional(3D)electrode structuring)are discussed for alkaline-fed systems,alongside emerging applications in seawater and pure-water electrolysis.By correlating material innovations with device-level metrics,this work provides a roadmap to address scalability challenges,offering perspectives on advancing AEMWEs for sustainable,large-scale hydrogen production.
