▎ 摘　　要

Catalytic performance of nickel cathodes for hydrogen production by water splitting can be improved by carbon nanomaterials, in particular graphene and reduced graphene oxide (rGO). In this work, electrodeposits Ni/rGO were examined in 0.1 M Na2SO4 with emphasis on hydrogen evolution reaction (HER) and effect of anodic oxidation. Ni and Ni/rGO were electrodeposited by galvanic square wave method with sonication. In contrast to smooth deposits of Ni, deposits of Ni/rGO had the cumulus/cauliflower type morphology with developed surface. Their increased surface area was confirmed by measurements of double layer capacitance. HER and anodic polarization currents were for Ni/rGO significantly higher than those for Ni. Voltammetric cycling or potentiostatic polarization to and above potentials of stability of Ni oxides (Ni3O4, Ni2O3 or NiO2) caused a rise in HER for both materials, but especially strongly for Ni/rGO. Enhanced HER on Ni/rGO was explained by greater surface area and the formation of larger amounts of electrocatalytic Ni oxides/hydroxides, as a result of the increased anodic reactivity of rGO-containing Ni. Incorporated rGO might also contribute by increasing electronic conductivity.