Enhanced Hydrogen Evolution Activity of Ni[MoS2] Hybrids in Alkaline Electrolyte

摘要

In this paper is presented a simple one-pot synthesis of a composite electrode with a non-noble metal for the catalysis of hydrogen evolution reaction in alkaline media. The Ni[MoS2] composite electrocatalyst has been synthesized by nickel electrodeposition on nickel electrodes with a conventional Ni-Watts plating bath containing MoS2 particles. This method was selected as it allows obtaining a great interaction between the nickel and the MoS2 in order to maximize the synergistic effect between the materials. Thus, electrodes with catalytic activity for hydrogen evolution reaction (HER) six times higher than the recorded from conventional Ni-Watts catalysts, were obtained in a reproducible and scalable way, which is suitable for industrial applications. Structural and spectroscopic characterizations indicate that the presence of MoS2 particles in the nickel matrix modifies the original properties of the metal. Evaluation of the electrodes electroactivity for HER was carried out by potentiodynamic scans, chronoamperometry, and electrochemical impedance spectroscopy in alkaline electrolyte. A Tafel slope of - 0.12 V dec(-1) was found, which is consistent with a two-electron transfer process, i.e., the Volmer reaction being the rate-determining step.