A novel electrodeposited nanocatalyst of nickel nanoparticles and reduced graphene oxide doped with halogens for hydrogen evolution reaction

Developing non-noble and high-performance metal hydrogen evolution reaction (HER) electrocatalysts is significant for hydrogen production. Doping heteroatoms on the surface of graphene is another amazing measure to improve the catalytic behavior of catalysts. In this work, halogen-doped reduced graphene oxide with nickel nanoparticles (Ni-XRGO) was investigated as an innovative electrocatalyst for the HER. The scanning electron microscopy images of the Ni-XRGO catalyst showed the leaf-like structure morphology with wide distribution. Also, the energy-dispersive X-ray spectroscopy, mapping technique, confirmed that the presence of halogens caused the homogenous distribution of Ni nanoparticles. X-ray diffraction technique confirmed the presence of doped halogens in reduced graphene oxide. The Ni-XRGO electrode with only 61 mV vs. RHE onset potential, 41 mV dec^-1 Tafel slope, good lifetime stability, and low charge transfer resistance could be a promising cathodic electrode for catalysis of HER. The particular electrochemical performance is due to the influence of the halogen elements on the charge distribution of the graphene surface; this leads to an enhancement in the exposure of additional active sites and an extension of the electrochemical active area. Our study presents a novel approach to the development of non-precious metal electrocatalysts that are both highly efficient and cost-effective for HER.