NiMo-based nanostructures are among the most active hydrogen evolution reaction(HER)catalysts under an alkaline environment due to their strong water dissociation ability.However,these nanostructures are vulnerable to...NiMo-based nanostructures are among the most active hydrogen evolution reaction(HER)catalysts under an alkaline environment due to their strong water dissociation ability.However,these nanostructures are vulnerable to the destructive effects of H_(2) production,especially at industry-standard current densities.Therefore,developing a strategy to improve their mechanical strength while maintaining or even further increasing the activity of these nanocatalysts is of great interest to both the research and industrial communities.Here,a hierarchical interconnected NiMoN(HW-NiMoN-2h)with a nanorod-nanowire morphology was synthesized based on a rational combination of hydrothermal and water bath processes.HW-NiMoN-2h is found to exhibit excellent HER activity due to the accomodation of abundant active sites on its hierarchical morphology,in which nanowires con-nect free-standing nanorods,concurrently strengthening its structural stability to withstand H_(2) production at 1 A cm^(−2).Seawater is an attractive feedstock for water electrolysis since H_(2) generation and water desalination can be addressed simultaneously in a single process.The HER performance of HW-NiMoN-2h in alkaline seawater suggests that the presence of Na+ions interferes with the reation kinetics,thus lowering its activity slightly.However,benefiting from its hierarchical and interconnected characteristics,HW-NiMoN-2h is found to deliver outstanding HER activity of 1 A cm^(−2) at 130 mV overpotential and to exhibit excellent stability at 1 A cm^(−2) over 70 h in 1 M KOH seawater.展开更多
Electrochemical water splitting driven by clean and sustainable energy sources to produce hydrogen is an efficient and environmentally friendly energy conversion technology.Water splitting involves hydrogen evolution ...Electrochemical water splitting driven by clean and sustainable energy sources to produce hydrogen is an efficient and environmentally friendly energy conversion technology.Water splitting involves hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),in which OER is the limiting factor and has attracted extensive research interest in the past few years.Conventional noble-metal-based OER electrocatalysts like IrO_(2) and RuO_(2) suffer from the limitations of high cost and scarce availability.Developing innovative alternative nonnoble metal electrocatalysts with high catalytic activity and long-term durability to boost the OER process remains a significant challenge.Among all of the candidates for OER catalysis,selfsupported layered double hydroxides(LDHs)have emerged as one of the most promising types of electrocatalysts due to their unique layered structures and high electrocatalytic activity.In this review,we summarize the recent progress on self-supported LDHs and highlight their electrochemical catalytic performance.Specifically,synthesis methods,structural and compositional parameters,and influential factors for optimizing OER performance are discussed in detail.Finally,the remaining challenges facing the development of self-supported LDHs are discussed and perspectives on their potential for use in industrial hydrogen production through water splitting are provided to suggest future research directions.展开更多
基金Element Resources,LLC,and Shell through UHETI,funded part of this work
文摘NiMo-based nanostructures are among the most active hydrogen evolution reaction(HER)catalysts under an alkaline environment due to their strong water dissociation ability.However,these nanostructures are vulnerable to the destructive effects of H_(2) production,especially at industry-standard current densities.Therefore,developing a strategy to improve their mechanical strength while maintaining or even further increasing the activity of these nanocatalysts is of great interest to both the research and industrial communities.Here,a hierarchical interconnected NiMoN(HW-NiMoN-2h)with a nanorod-nanowire morphology was synthesized based on a rational combination of hydrothermal and water bath processes.HW-NiMoN-2h is found to exhibit excellent HER activity due to the accomodation of abundant active sites on its hierarchical morphology,in which nanowires con-nect free-standing nanorods,concurrently strengthening its structural stability to withstand H_(2) production at 1 A cm^(−2).Seawater is an attractive feedstock for water electrolysis since H_(2) generation and water desalination can be addressed simultaneously in a single process.The HER performance of HW-NiMoN-2h in alkaline seawater suggests that the presence of Na+ions interferes with the reation kinetics,thus lowering its activity slightly.However,benefiting from its hierarchical and interconnected characteristics,HW-NiMoN-2h is found to deliver outstanding HER activity of 1 A cm^(−2) at 130 mV overpotential and to exhibit excellent stability at 1 A cm^(−2) over 70 h in 1 M KOH seawater.
基金L.W.and X.X.acknowledge the support from the China Scholarship CouncilZ.R.acknowledges the Research Award from the Alexander von Humboldt Foundation and Professor Kornelius Nielsch at IFW Dresden Germany.
文摘Electrochemical water splitting driven by clean and sustainable energy sources to produce hydrogen is an efficient and environmentally friendly energy conversion technology.Water splitting involves hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),in which OER is the limiting factor and has attracted extensive research interest in the past few years.Conventional noble-metal-based OER electrocatalysts like IrO_(2) and RuO_(2) suffer from the limitations of high cost and scarce availability.Developing innovative alternative nonnoble metal electrocatalysts with high catalytic activity and long-term durability to boost the OER process remains a significant challenge.Among all of the candidates for OER catalysis,selfsupported layered double hydroxides(LDHs)have emerged as one of the most promising types of electrocatalysts due to their unique layered structures and high electrocatalytic activity.In this review,we summarize the recent progress on self-supported LDHs and highlight their electrochemical catalytic performance.Specifically,synthesis methods,structural and compositional parameters,and influential factors for optimizing OER performance are discussed in detail.Finally,the remaining challenges facing the development of self-supported LDHs are discussed and perspectives on their potential for use in industrial hydrogen production through water splitting are provided to suggest future research directions.
