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–HG_0.5/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–HG_0.5/NF catalyst