Microstructure and Hydrogen Evolution Catalytic Properties of Ni/CNTs-SnO2 Prepared by Electrodeposition Method

Abstract

The Ni/CNTs-SnO₂ composite electrodes were prepared by the composite electrodeposition method. The influence of the incorporation of CNTs-SnO₂ on the hydrogen evolution reaction (HER) of Ni coating was investigated. The Ni/CNTs-SnO₂ composite electrodes were demonstrated successfully by SEM, XRD and EDX. The physical characterization indicated that the average sizes of the CNTs-SnO₂ particles were about 120 nm. The incorporation of CNTs-SnO₂ had been altered the preferred orientation of Ni coatings and the microscopic morphology of composite coatings. The Ni/CNTs-SnO₂ composite electrodes were tested by LSV, Tafel, EIS and CP to define their catalytic activity and stability for the HER. Compared with the Ni coating, the Ni/CNTs-SnO₂ composite electrodes had a larger specific surface area, which could provide more catalytic active sites for the HER. The overpotential of the HER was reduced. The electrocatalytic hydrogen evolution performance of the composite electrodes were improved. At a cathodic current density of 10 mA/cm², the Ni/CNTs-SnO₂ composite electrodes prepared with 0.75 g/L of CNTs-SnO₂ displayed a lowest overpotential (259 mV) for HER, which demonstrated the highest catalytic activity for HER.