Binder-free nickel/boron-doped diamond film electrodes for hydrogen evolution reaction in alkaline medium: Effect of nickel catalyst nanostructure on electrochemical performance

Abstract

Boron-doped diamond (BDD) is a robust electrode material, and Ni metal is a promising alternative electrocatalyst to noble metals for promoting the hydrogen evolution reaction. In this study, binder-free Ni/BDD film electrodes, with Ni acting as a catalyst, were constructed. With thermal annealing temperature regulation, the Ni catalyst exhibited different nanostructures, including amorphous continuous films, partially crystalline corrugated films, and uniformly dispersive nanoparticles. The electrodes were characterized via scanning electron microscopy, grazing-incidence X-ray diffraction, and X-ray photoelectron spectroscopy. Furthermore, the impact of the Ni catalyst fine structure on the hydrogen evolution reaction performance was evaluated. The results highlighted the versatility of BDD as a platform for developing binder-free Ni/BDD electrodes. Through precise adjustment of the nano-scale structure of Ni catalysts on the BDD surface, high hydrogen evolution reaction activity was achieved, with an overpotential as low as 273 mV at 10 mA/cm2 in a 1 M KOH solution.