In this work,we demonstrated the enhanced oxygen evolution reaction（OER） activity of flower-shaped cobalt-nickel oxide（NiCo_2O_4） decorated with iridium-nickel bimetal as an electrode material.The samples were pre...In this work,we demonstrated the enhanced oxygen evolution reaction（OER） activity of flower-shaped cobalt-nickel oxide（NiCo_2O_4） decorated with iridium-nickel bimetal as an electrode material.The samples were prepared by carefully depositing pre-synthesized IrNi nanopartides on the surfaces of the NiCo_2O_4 nano-flowers.Compared with bare NiCo_2O_4,IrNi,and IrNi/Co_3O_4,the IrNi/NiCo_2O_4 exhibited significantly enhanced electrocatalytic activity in the OER,including a lower overpotential of 210 mV and a higher current density at an overpotential of 540 mV.We found that the IrNi/NiCo_2O_4 showed more efficient electron transport behavior and reduced polarization because of its bimetal IrNi modification by analyzing its Tafel slope and turnover frequency.Furthermore,the electrocatalytic mechanism of IrNi/NiCo_2O_4 in the OER was studied,and it was found that the combined active sites of the composite effectively improved the rate determining step.The synergic effect of the bimetal and metal oxide plays an important role in this reaction,enhancing the transmission efficiency of electrons and providing more active sites for the OER.The results reveal that IrNi/NiCo_2O_4 is an excellent electrocatalyst for OER.展开更多
基金supported by the National Natural Science Foundation of China(61371021 and 61671284)the support of Shanghai Education Commission(Peak Discipline Construction)
文摘In this work,we demonstrated the enhanced oxygen evolution reaction（OER） activity of flower-shaped cobalt-nickel oxide（NiCo_2O_4） decorated with iridium-nickel bimetal as an electrode material.The samples were prepared by carefully depositing pre-synthesized IrNi nanopartides on the surfaces of the NiCo_2O_4 nano-flowers.Compared with bare NiCo_2O_4,IrNi,and IrNi/Co_3O_4,the IrNi/NiCo_2O_4 exhibited significantly enhanced electrocatalytic activity in the OER,including a lower overpotential of 210 mV and a higher current density at an overpotential of 540 mV.We found that the IrNi/NiCo_2O_4 showed more efficient electron transport behavior and reduced polarization because of its bimetal IrNi modification by analyzing its Tafel slope and turnover frequency.Furthermore,the electrocatalytic mechanism of IrNi/NiCo_2O_4 in the OER was studied,and it was found that the combined active sites of the composite effectively improved the rate determining step.The synergic effect of the bimetal and metal oxide plays an important role in this reaction,enhancing the transmission efficiency of electrons and providing more active sites for the OER.The results reveal that IrNi/NiCo_2O_4 is an excellent electrocatalyst for OER.
