Study of Ni-S/CeO2 composite material for hydrogen evolution reaction in alkaline solution

Ni-S/CeO2 composite materials for hydrogen evolution reaction (HER) have been prepared by an electrodeposition method under supergravity field from nickel sulfamate. With the different mass concentrations of CeO2, the morphology and X-ray diffraction patterns of Ni-S/CeO2 are diverse. Apparently, the CeO2 contents of Ni-S/CeO2 composite electrodes under supergravity fields are higher than that under normal gravity field. In addition, the HER catalytic activity of Ni-S/CeO2 composite electrodes can be measured in 1.0 M NaOH at 298 K. The results show that overpotential of Ni-S/CeO2 electrode of 7 g/L CeO2 under 3000 rpm is the least, suggesting perhaps too much content of CeO2 hinder the desorption of Hads, or too little CeO2 can not play palpable roles in improving the catalytic activity and increasing oxygen vacancies. And the exchange current density j0 value of Ni-S/CeO2 composite electrode prepared under the speed of 3000 rpm, which is 1.16 times larger than the Ni-S/CeO2 of 0 g/L CeO2, is 1.9 times higher than that under normal gravity field. EIS results suggest that there exists a synergetic effect on HER between CeO2 and Ni-S alloy matrix.