Two-dimensional(2D)metal organic frameworks(MOFs)are emerging as low-cost oxygen evolution reaction(OER)electrocatalysts,however,suffering aggregation and poor operation stability.Herein,ultrafine Fe_(3)O_(4) nanopart...Two-dimensional(2D)metal organic frameworks(MOFs)are emerging as low-cost oxygen evolution reaction(OER)electrocatalysts,however,suffering aggregation and poor operation stability.Herein,ultrafine Fe_(3)O_(4) nanoparticles(diameter:6±2 nm)are homogeneously immobilized on 2D Ni based MOFs(Ni-BDC,thickness:5±1 nm)to improve the OER stability.Electronic structure modulation for enhanced catalytic activity is studied via adjusting the amount of Fe_(3)O_(4) nanoparticles on Ni-BDC.The optimal Fe_(3)O_(4)/Ni-BDC achieves the best OER performance with an overpotential of 295 mV at 10 mA cm^(-2),a Tafel slope of 47.8 mV dec^(-1) and a considerable catalytic durability of more than 40 h(less than 5 h for Ni-BDC alone).DFT calculations confirm that the active sites for Fe_(3)O_(4)/Ni-BDC are mainly contributed by Fe species with a higher oxidation state,and the potential-determining step(PDS)is the formation of the adsorbed O*species,which are facilitated in the composite.展开更多
基金support from the Chinese Scholarship Council(201706220080)for W.H.the Natural Science Foundation of Hunan Province(2019JJ50526)for C.P.+1 种基金The Danish Council for Independent Research for the YDUN project(DFF 4093-00297)to J.Z.Villum Experiment(grant No.35844)for X.X.
文摘Two-dimensional(2D)metal organic frameworks(MOFs)are emerging as low-cost oxygen evolution reaction(OER)electrocatalysts,however,suffering aggregation and poor operation stability.Herein,ultrafine Fe_(3)O_(4) nanoparticles(diameter:6±2 nm)are homogeneously immobilized on 2D Ni based MOFs(Ni-BDC,thickness:5±1 nm)to improve the OER stability.Electronic structure modulation for enhanced catalytic activity is studied via adjusting the amount of Fe_(3)O_(4) nanoparticles on Ni-BDC.The optimal Fe_(3)O_(4)/Ni-BDC achieves the best OER performance with an overpotential of 295 mV at 10 mA cm^(-2),a Tafel slope of 47.8 mV dec^(-1) and a considerable catalytic durability of more than 40 h(less than 5 h for Ni-BDC alone).DFT calculations confirm that the active sites for Fe_(3)O_(4)/Ni-BDC are mainly contributed by Fe species with a higher oxidation state,and the potential-determining step(PDS)is the formation of the adsorbed O*species,which are facilitated in the composite.
