The most abundant rare earth metals in the Earth’s crust have received considerable recent attention as efficient electrocatalysts for full water splitting,but it is highly desired to explore a new strategy to improv...The most abundant rare earth metals in the Earth’s crust have received considerable recent attention as efficient electrocatalysts for full water splitting,but it is highly desired to explore a new strategy to improve their catalytic activity.In this communication,we report the development of nanoporous CeO_(2) nanowire array on Ti mesh(np-CeO_(2)/TM)derived from MnO_(2)–CeO_(2)/TM via an acid etching strategy,and MnO_(2) acts as a pore-forming agent through selective etching with oxalic acid.As a rare earth metal catalyst,np-CeO_(2)/TM needs an overpotential of 91 mV for the hydrogen evolution reaction(HER)and 279 mV for the oxygen evolution reaction(OER)to drive a current density of 10 mV cm^(−2) in 1.0 M KOH,93 mV and 101 mV less than that needed by MnO_(2)–CeO_(2)/TM,respectively.We also demonstrate the use of np-CeO_(2)/TM to make a two-electrode electrolyzer capable of driving 10 mV cm^(−2) at a cell voltage of 1.57 V.展开更多
The oxygen evolution reaction(OER)is the key anode reaction for electrochemical water splitting,but it is severely hindered by the sluggish reaction kinetics and insufficient stability of traditional electrocatalysts....The oxygen evolution reaction(OER)is the key anode reaction for electrochemical water splitting,but it is severely hindered by the sluggish reaction kinetics and insufficient stability of traditional electrocatalysts.To address the urgent need for efficient and low-cost electrocatalysts,a promising heterogeneous CoFelayered double hydroxide-based electrocatalyst(Ce@CoFe-LDH)is developed by a one-step hydrothermal method combined with rapid electrodeposition.The ultrafine Ce(OH)_(3) nanoparticles effectively trigger the local surface activity of CoFe-LDH nanowires by the interface electron transfer,thereby promoting the improvement of OER activity and stability.Consequently,the Ce@CoFe-LDH electrocatalyst only needs a 207 mV overpotential to reach 10 mA cm^(-2),while the Tafel slope is only 50.0 mV dec^(-1),smaller than those of the CoFe-LDH catalyst(232 mV,74.2 mV dec^(-1),respectively).Importantly,the Ce@CoFe-LDH electrocatalyst exhibits remarkable catalytic durability toward the OER at 100 mA cm^(-2) over 120 hours.First-principles theoretical calculations reveal that interface engineering can be used to optimize the electronic structure of Ce@CoFe-LDH by charge redistribution and thereby decrease the energy barrier of the rate-determining step.In addition,the Ce@CoFe-LDH electrocatalyst as an anode for water splitting also shows a low cell potential of 1.47 V at 10 mA cm^(-2) and robust stability at 100 mA cm^(-2) over 50 hours.Overall,this work provides new insights into designing efficient OER electrocatalysts for scalable water splitting in clean energy and environmental applications.展开更多
Polymeric carbon nitride(PCN)materials,as an emerging class of metal-free photocatalysts,have demonstrated significant potential in the field of solar energy conversion,particularly in areas of water splitting.But the...Polymeric carbon nitride(PCN)materials,as an emerging class of metal-free photocatalysts,have demonstrated significant potential in the field of solar energy conversion,particularly in areas of water splitting.But the utilization of PCN is restricted by its high carrier recombination rate and low charge transfer efficiency.In order to address these challenges,this work involves choosing pyridyl organic small molecules of nicotinic acid(NA)and melamine to construct donor–acceptor(D–A)-structured carbon nitride nanotubes.Pyridine heterocyclic rings are converged at the edge of the PCN structure via supramolecular self-assembly,facilitating the fabrication of donor–acceptor-structured carbon nitride nanotubes.The pyridine heterocyclic rings,with their strong electronic ability,create a preferred pathway for electronic transfer.This effectively mitigates carrier recombination within the molecular plane.In addition,the unique hollow tubular structure of carbon nitride nanotubes enhances their visible light absorption ability,expands the surface area of the catalyst,and then increases the number of catalytically active sites,which consequently enhances photocatalytic performance.The H_(2)production rates of one-dimensional tubular carbon nitride doped with 100 mg of NA(designated as NA100-CN)is 2584.2μmol g^(−1)h^(−1),which is 4.7 times that of pristine PCN.This investigation elucidates the mechanism of charge transfer from D to A,describing the response mechanism of photocatalysis,with profound implications for advancing clean energy,environmental preservation and sustainable development.展开更多
基金supported by the National Natural Science Foundation of China(no.21575137).
文摘The most abundant rare earth metals in the Earth’s crust have received considerable recent attention as efficient electrocatalysts for full water splitting,but it is highly desired to explore a new strategy to improve their catalytic activity.In this communication,we report the development of nanoporous CeO_(2) nanowire array on Ti mesh(np-CeO_(2)/TM)derived from MnO_(2)–CeO_(2)/TM via an acid etching strategy,and MnO_(2) acts as a pore-forming agent through selective etching with oxalic acid.As a rare earth metal catalyst,np-CeO_(2)/TM needs an overpotential of 91 mV for the hydrogen evolution reaction(HER)and 279 mV for the oxygen evolution reaction(OER)to drive a current density of 10 mV cm^(−2) in 1.0 M KOH,93 mV and 101 mV less than that needed by MnO_(2)–CeO_(2)/TM,respectively.We also demonstrate the use of np-CeO_(2)/TM to make a two-electrode electrolyzer capable of driving 10 mV cm^(−2) at a cell voltage of 1.57 V.
基金financially supported by the National Key R&D Program of China(2022YFC3500500 and 2022YFC3500502)the Anhui Provincial Natural Science Foundation(no.2208085MA16)partial support from the Australian Research Council(ARC)and QUT Centre for Materials Science.
文摘The oxygen evolution reaction(OER)is the key anode reaction for electrochemical water splitting,but it is severely hindered by the sluggish reaction kinetics and insufficient stability of traditional electrocatalysts.To address the urgent need for efficient and low-cost electrocatalysts,a promising heterogeneous CoFelayered double hydroxide-based electrocatalyst(Ce@CoFe-LDH)is developed by a one-step hydrothermal method combined with rapid electrodeposition.The ultrafine Ce(OH)_(3) nanoparticles effectively trigger the local surface activity of CoFe-LDH nanowires by the interface electron transfer,thereby promoting the improvement of OER activity and stability.Consequently,the Ce@CoFe-LDH electrocatalyst only needs a 207 mV overpotential to reach 10 mA cm^(-2),while the Tafel slope is only 50.0 mV dec^(-1),smaller than those of the CoFe-LDH catalyst(232 mV,74.2 mV dec^(-1),respectively).Importantly,the Ce@CoFe-LDH electrocatalyst exhibits remarkable catalytic durability toward the OER at 100 mA cm^(-2) over 120 hours.First-principles theoretical calculations reveal that interface engineering can be used to optimize the electronic structure of Ce@CoFe-LDH by charge redistribution and thereby decrease the energy barrier of the rate-determining step.In addition,the Ce@CoFe-LDH electrocatalyst as an anode for water splitting also shows a low cell potential of 1.47 V at 10 mA cm^(-2) and robust stability at 100 mA cm^(-2) over 50 hours.Overall,this work provides new insights into designing efficient OER electrocatalysts for scalable water splitting in clean energy and environmental applications.
基金financially supported by the National Natural Science Foundation of China(22202086,22208129)the Huaian City Science and Technology Plan Project(HAG202303).
文摘Polymeric carbon nitride(PCN)materials,as an emerging class of metal-free photocatalysts,have demonstrated significant potential in the field of solar energy conversion,particularly in areas of water splitting.But the utilization of PCN is restricted by its high carrier recombination rate and low charge transfer efficiency.In order to address these challenges,this work involves choosing pyridyl organic small molecules of nicotinic acid(NA)and melamine to construct donor–acceptor(D–A)-structured carbon nitride nanotubes.Pyridine heterocyclic rings are converged at the edge of the PCN structure via supramolecular self-assembly,facilitating the fabrication of donor–acceptor-structured carbon nitride nanotubes.The pyridine heterocyclic rings,with their strong electronic ability,create a preferred pathway for electronic transfer.This effectively mitigates carrier recombination within the molecular plane.In addition,the unique hollow tubular structure of carbon nitride nanotubes enhances their visible light absorption ability,expands the surface area of the catalyst,and then increases the number of catalytically active sites,which consequently enhances photocatalytic performance.The H_(2)production rates of one-dimensional tubular carbon nitride doped with 100 mg of NA(designated as NA100-CN)is 2584.2μmol g^(−1)h^(−1),which is 4.7 times that of pristine PCN.This investigation elucidates the mechanism of charge transfer from D to A,describing the response mechanism of photocatalysis,with profound implications for advancing clean energy,environmental preservation and sustainable development.
