Encapsulated Ni nanoparticles in the incomplete graphite layer anchored on NiMo oxides enabling superior hydrogen evolution to Pt

Abstract

Developing non-precious metal catalysts, with superior activity to Pt, remains a great challenge for the hydrogen evolution reaction (HER) in alkaline solution. Herein, encapsulated Ni nanoparticles in the incomplete graphite layer anchored on nanobelts consisting of Ni oxide and Mo oxide (IG@Ni-NiMoO_x) are developed by etching–hydrolysis and subsequent annealing treatment. IG@Ni-NiMoO_x has higher HER activity than Pt regarding its Tafel slope and overpotential at −10 and −100 mA cm⁻², and also shows negligible decline over 300 h at −200 mA cm⁻². Theoretical calculations reveal that the exposed Ni possesses superior water-dissociation activity to Pt and the encapsulated Ni in graphene decreases the binding strength of Ni with hydrogen, improving HER activity. Overall, this work not only offers non-precious metal catalysts with superior HER activity to Pt, but also provides crucial insights into designing efficient HER catalysts in alkaline solution.