Electrochemical synthesis of Ni–S/CeO2 composite electrodes for hydrogen evolution reaction

Ni–S/CeO2 electrodes have been prepared by a composite electrodeposition technique using nickel sulfaminate bath containing suspended micro- or nano-sized CeO2 particles. The composite electrodes exhibit a high activity for the hydrogen evolution reaction (HER) in alkaline solutions, most likely due to the synergistic effects between Ni and CeO2, as well as the increased surface area of the electrodes upon addition of CeO2 particles. It is found that the addition of CeO2 particles can lead to an increase of the sulphur content, resulting in more amorphous structures in the composite coatings. The Ni–S/micro-CeO2 composite electrode yields a higher HER activity than that measured with Ni–S/nano-CeO2 electrode, which is 2.2 times higher than that on the Ni–S coating. The relevant discussion was provided to elucidate the promotional roles of CeO2 particles in the composite electrodeposition process and corresponding HER activity.

► The correlation of synthesis–structure–activity is studied on Ni–S/CeO2 coatings.
► The CeO2 particles embedded in Ni–S matrix can increase the HER activity.
► The addition of CeO2 particles can increase the sulphur content.
► The addition of CeO2 particles can increase the amorphous components.