Photoelectrochemical(PEC)water splitting holds significant promise for sustainable energy harvesting that enables efficient conversion of solar energy into green hydrogen.Nevertheless,achievement of high performance i...Photoelectrochemical(PEC)water splitting holds significant promise for sustainable energy harvesting that enables efficient conversion of solar energy into green hydrogen.Nevertheless,achievement of high performance is often limited by charge carrier recombination,resulting in unsatisfactory saturation current densities.To address this challenge,we present a novel strategy for achieving ultrahigh current density by incorporating a bridge layer between the Si substrate and the NiOOH cocatalyst in this paper.The optimal photoanode(TCO/n-p-Si/TCO/Ni)shows a remarkably low onset potential of 0.92 V vs.a reversible hydrogen electrode and a high saturation current density of 39.6 mA·cm^(-2),which is about 92.7%of the theoretical maximum(42.7 mA·cm^(-2)).In addition,the photoanode demonstrates stable operation for 60 h.Our systematic characterizations and calculations demonstrate that the bridge layer facilitates charge transfer,enhances catalytic performance,and provides corrosion protection to the underlying substrate.Notably,the integration of this photoanode into a PEC device for overall water splitting leads to a reduction of the onset potential.These findings provide a viable pathway for fabricating highperformance industrial photoelectrodes by integrating a substrate and a cocatalyst via a transparent and conductive bridge layer.展开更多
Large-scale green hydrogen production technology,based on the electrolysis of water powered by renewable energy,relies heavily on non-precious metal oxygen evolution reactions(OER)electrocatalysts with high activity a...Large-scale green hydrogen production technology,based on the electrolysis of water powered by renewable energy,relies heavily on non-precious metal oxygen evolution reactions(OER)electrocatalysts with high activity and stability under industrial conditions(6 M KOH,60℃-80℃)at large current density.Here,we construct Fe and Co co-incorporated nickel(oxy)hydroxide(Fe_(2.5)Co_(2.5)Ni_(10)O_(y)H_(z)@NFF)via a multi-metal electrodeposition,which exhibits outstanding OER performance(overpotential:185 mV@10 mA cm^(-2)).Importantly,an overwhelming stability for more than 1100 h at 500 mA cm^(-2)under industrial conditions is achieved.Our combined experimental and computational investigation reveals the surface-reconstructedγ-NiOOH with a high valence state is the active layer,where the optimal(Fe,Co)co-incorporation tunes its electronic structure,changes the potential determining step,and reduces the energy barrier,leading to ultrahigh activity and stability.Our findings demonstrate a facile way to achieve an electrocatalyst with high performance for the industrial production of green hydrogen.展开更多
The incorporation of high-valence metals into FeCoNi-based oxide/hydroxide/oxyhydroxide matrices is widely acknowledged as an effective approach to enhance oxygen evolution reaction(OER)performance.Traditionally,it is...The incorporation of high-valence metals into FeCoNi-based oxide/hydroxide/oxyhydroxide matrices is widely acknowledged as an effective approach to enhance oxygen evolution reaction(OER)performance.Traditionally,it is assumed that these metals could maintain structural stability during operation.Here,our in-situ and ex-situ characterizations reveal that the dynamic electro-dissolution behavior of Mo^(6+)and W^(6+)species in FeCoNiMoW pre-catalyst leads to fast formation of catalytic-active(Mo,W)co-incorporated metal oxyhydroxides,which play a key role in the OER performance.This leaching process enables structural reconstruction,while concurrently optimizing the adsorption of the oxygen intermediate.The resulting catalyst exhibits exceptional OER activity,achieving an overpotential of 218 mV at 10 mA cm^(-2),as well as remarkable stability with a degradation rate of only 8.7μV h^(-1)over 720 h at 500 mA cm^(-2).Furthermore,anion-exchange membrane water electrolyzers based on FeCoNiMoW//Pt/C can stably operate at 500 and 1000 mA cm^(-2)with low cell voltages of 1.70 and 1.84 V,respectively.The cost of the electric bill using this catalyst is notably low,at only$0.88 per kg,which is significantly below target of$2.00 per kg set by the U.S.Office of Clean Energy(OCE)for 2026.These findings offer valuable insights into the critical role of high-valence metals in advancing the OER process and underscore the substantial potential of this approach for industrial scale-up applications.展开更多
基金supported by Multi-Year Research Grants from the University of Macao(MYRG-GRG2023-00010-IAPME,MYRG-GRG2024-00038-IAPME,MYRG2022-00026-IAPME)the Science and Technology Development Fund(FDCT)from Macao SAR(0023/2023/AFJ,0050/2023/RIB2,006/2022/ALC,0087/2024/AFJ,0111/2022/A2).
文摘Photoelectrochemical(PEC)water splitting holds significant promise for sustainable energy harvesting that enables efficient conversion of solar energy into green hydrogen.Nevertheless,achievement of high performance is often limited by charge carrier recombination,resulting in unsatisfactory saturation current densities.To address this challenge,we present a novel strategy for achieving ultrahigh current density by incorporating a bridge layer between the Si substrate and the NiOOH cocatalyst in this paper.The optimal photoanode(TCO/n-p-Si/TCO/Ni)shows a remarkably low onset potential of 0.92 V vs.a reversible hydrogen electrode and a high saturation current density of 39.6 mA·cm^(-2),which is about 92.7%of the theoretical maximum(42.7 mA·cm^(-2)).In addition,the photoanode demonstrates stable operation for 60 h.Our systematic characterizations and calculations demonstrate that the bridge layer facilitates charge transfer,enhances catalytic performance,and provides corrosion protection to the underlying substrate.Notably,the integration of this photoanode into a PEC device for overall water splitting leads to a reduction of the onset potential.These findings provide a viable pathway for fabricating highperformance industrial photoelectrodes by integrating a substrate and a cocatalyst via a transparent and conductive bridge layer.
基金supported by the Science and Technology Development Fund(FDCT)from Macao SAR(0050/2023/RIB2,0023/2023/AFJ,006/2022/ALC,0111/2022/A2,0105/2023/RIA2)Multi-Year Research Grants(MYRG-GRG2023-00010-IAPME,and MYRG2022-00026-IAPME)from Research&Development Office at University of MacaoShenzhen-Hong Kong-Macao Science and Technology Research Programme(Type C)(SGDX20210823103803017)from Shenzhen.
文摘Large-scale green hydrogen production technology,based on the electrolysis of water powered by renewable energy,relies heavily on non-precious metal oxygen evolution reactions(OER)electrocatalysts with high activity and stability under industrial conditions(6 M KOH,60℃-80℃)at large current density.Here,we construct Fe and Co co-incorporated nickel(oxy)hydroxide(Fe_(2.5)Co_(2.5)Ni_(10)O_(y)H_(z)@NFF)via a multi-metal electrodeposition,which exhibits outstanding OER performance(overpotential:185 mV@10 mA cm^(-2)).Importantly,an overwhelming stability for more than 1100 h at 500 mA cm^(-2)under industrial conditions is achieved.Our combined experimental and computational investigation reveals the surface-reconstructedγ-NiOOH with a high valence state is the active layer,where the optimal(Fe,Co)co-incorporation tunes its electronic structure,changes the potential determining step,and reduces the energy barrier,leading to ultrahigh activity and stability.Our findings demonstrate a facile way to achieve an electrocatalyst with high performance for the industrial production of green hydrogen.
基金Science and Technology Development Fund from Macao SAR(FDCT)(0111/2022/A2,0050/2023/RIB2,0023/2023/AFJ,0002/2024/TFP,and 0087/2024/AFJ)Multi-Year Research Grants(MYRG-GRG2025-00007-IAPME and MYRG-GRG2024-00038-IAPME)from the Research&Development Office at the University of Macao。
文摘The incorporation of high-valence metals into FeCoNi-based oxide/hydroxide/oxyhydroxide matrices is widely acknowledged as an effective approach to enhance oxygen evolution reaction(OER)performance.Traditionally,it is assumed that these metals could maintain structural stability during operation.Here,our in-situ and ex-situ characterizations reveal that the dynamic electro-dissolution behavior of Mo^(6+)and W^(6+)species in FeCoNiMoW pre-catalyst leads to fast formation of catalytic-active(Mo,W)co-incorporated metal oxyhydroxides,which play a key role in the OER performance.This leaching process enables structural reconstruction,while concurrently optimizing the adsorption of the oxygen intermediate.The resulting catalyst exhibits exceptional OER activity,achieving an overpotential of 218 mV at 10 mA cm^(-2),as well as remarkable stability with a degradation rate of only 8.7μV h^(-1)over 720 h at 500 mA cm^(-2).Furthermore,anion-exchange membrane water electrolyzers based on FeCoNiMoW//Pt/C can stably operate at 500 and 1000 mA cm^(-2)with low cell voltages of 1.70 and 1.84 V,respectively.The cost of the electric bill using this catalyst is notably low,at only$0.88 per kg,which is significantly below target of$2.00 per kg set by the U.S.Office of Clean Energy(OCE)for 2026.These findings offer valuable insights into the critical role of high-valence metals in advancing the OER process and underscore the substantial potential of this approach for industrial scale-up applications.
