摘要
Now,Pt-based materials are still the best catalysts for hydrogen evolution reaction(HER).Nevertheless,the scarcity of Pt makes it impossible for the large-scale applications in industry.Although cobalt is taken as an excellent HER catalyst due to its suitable H*binding,its alkali HER catalytic property need to be improved because of the sluggish water dissociation kinetics.In this work,nitrogen with small atomic radius and metallophilicity is employed to adjust local charges of atomically dispersed Mo^(δ+)sites on Co nanosheets to trigger water dissociation.Theoretical calculations suggest that the energy barrier of water dissociation can be effectively reduced by introducing nitrogen coordinated Mo^(δ+)sites.To realize this speculation,atomically dispersed Mo^(δ+)sites with nitrogen coordination of Mo(N)/Co were prepared via reconstruction of CoMoO_(4).High angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)and X-ray absorption spectroscopy(XAS)demonstrate the coordination of N atoms with atomically dispersed Mo atoms,leading to the local charges of atomically dispersed Mo^(δ+)sites in Mo(N)/Co.The measurement from ambient pressure X-ray photoelectron spectroscopy(AP-XPS)reveals that the Mo^(δ+)sites promote the adsorption and activation of water molecule.Therefore,the Mo(N)/Co exhibits an excellent activity,which need only an overpotential of 39 mV to reach the current density of 10 mA cm^(-2).The proposed strategy provides an advance pathway to design and boost alkaline HER activity at the atomic-level.
基金
the International Science and Technology Cooperation Program(2017YFE0127800 and 2018YFE0203400)
the Natural Science Foundation of China(21872174,21762036 and U1932148)
the Hunan Provincial Science and Technology Program(2017XK2026)
the Shenzhen Science and Technology Innovation Project(JCYJ20180307151313532)
Innovation and Entrepreneurship Training Program for College Students(S202110670023)
the Natural Science Foundation of Science and Technology Department of Guizhou Province([2019]1297)
the Special Project of Science and Technology Department of Guizhou Province([2020]QNSYXM03)
the Natural Science Foundation of Education Department of Guizhou Province([2019]213,[2015]66)
Teaching Quality Improvement Project of Qiannan Normal University for Nationalities([2017]50)
the Beam Lines of BL01C1,BL24A1 in the NSRRC(MOST 109-2113-M-213-002)and beamline BL10B in National Synchrotron Radiation Laboratory。
