Effect of Ni Nanoparticles on HG Sheets Modified by GO on the Hydrogen Evolution Reaction

Ni-based compounds are being explored as an alternative for Pt in hydrogen evolution reactions. In this work, phenylhydrazine-4-sulfonic acid is utilized in the reduction of graphene oxide to synthesize novel hydrophilic graphene, and electrodeposition is used to synthesize Ni–HG/NF composite cathodes from a nickel sulphamate bath containing suspended-sized hydrophilic graphene. The Ni–HG0.5/NF composite coatings reveal prominent activity on the hydrogen evolution reaction in alkaline solutions with a high exchange current density of 5.012 mA cm–2, a low Tafel slope of 81 mV dec–1, and small overpotentials of 30 and 140 mV to obtain current densities of 10 and 100 mA cm–2. These results are attributed to hydrophilic reform of hydrophilic graphene, enhanced charge transfer between Ni and hydrophilic graphene, and the strong intensity of Ni(111) of Ni–HG0.5/NF catalyst.