Abstract:Ni-6W alloy strip with 70μm thick was used as substrate, nanoporous NiW was prepared by anodic oxidation method, and then CeO2 was deposited by chemical decomposition method on nanoporous NiW to prepare NiW-nano-CeO2 electrode. The morphology structure of the NiW, nanoporous NiW and NiW-nano-CeO2 three electrodes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and XPS. The electrochemical hydrogen evolution behaviors of the three electrodes were characterized by cathodic polarization curves, cyclic voltammetry curves and electrochemical impedance techniques. The results show that NiW-nano-CeO2 electrode has the highest electrocatalytic hydrogen evolution performance, which is mainly due to the three-dimensional nanoporous structure, small mass transfer impedance, large electrochemically active specific surface area and the synergistic effect between NiW and CeO2. When used as an electrocatalyst for hydrogen evolution, the current density reaches 100 mA cm-2 in 1M NaOH solution, it is 55 mV and 81 mV lower than that of NiW-CeO2 lectrode and NiW electrode, respectively. The impedance spectra obtained were fitted and analyzed, and the influence of CeO2 on the electrochemical process of the whole hydrogen evolution process was analyzed. The results show that the hydrogen evolution performance of the (200) crystal-exposed nano-porous NiW-CeO2 electrode is better than that of the Ni (111) crystal-exposed NiW-CeO2 electrode and the non-preferential orientation Ni-S/ CeO2, Ni-Zn/ CeO2 electrode. The composite electrode has a higher exchange current density of 1.7 × 10-1A cm-2 than the co-deposited Ni-CeO2 reported in the literature. In this paper, the morphology of CeO2 was controlled by this method, and then the (200) crystal face was selectively exposed to control the catalytic performance of NiW-CeO2 composite electrode for hydrogen evolution.