Effects of CeO2 on the microstructure and hydrogen evolution property of Ni–Zn coatings

In this work, high-performance Ni–Zn/CeO2 composite electrodes are prepared for hydrogen evolution reaction (HER) in alkaline solutions using a composite electrodeposition technique in a Ni–Zn bath containing suspended micro- or nano-sized CeO2 particles. The composite electrodes containing more CeO2 particles are dominant with laminate morphology. The addition of CeO2 particles can alter the electrode phase composition. Optimization of the concentration of CeO2 particles leads to a significant enhancement of HER activity on the composite electrodes, relative to Ni–Zn coating. The exchange current density of the composite electrode is 2 times higher than that of the Ni–Zn coating when the nano-CeO2 concentration is 1 g L−1. Electrochemical impedance spectroscopy results suggest that a possible synergetic effect on HER may exist between CeO2 particles and Ni–Zn matrix. ► The correlation of synthesis–structure–activity is studied on Ni–Zn/CeO2 coatings. ► The CeO2 particles embedded in Ni–Zn matrix can increase the HER activity. ► A synergetic effect between CeO2 particles and Ni–Zn matrix may exist in HER. ► The electrodes contained excess CeO2 particles showed laminate morphology.