Electrocatalytic performance of hollow structured nickel disulfide (NiS2) for hydrogen evolution reaction (HER) in acidic conditions

Abstract

The development of efficient catalysts for the hydrogen evolution reaction (HER) plays a critical role in water splitting for green hydrogen production. Due to the high cost of platinum, which is commonly used as an HER catalyst, extensive research has recently been conducted on non-noble metal-based catalysts. In this study, NiS2 catalysts were synthesized via a hydrothermal method as non-noble metal HER catalysts, and their electrochemical catalytic properties were investigated. The morphology of the hydrothermally synthesized NiS2 catalysts was controlled to form either hollow or non-hollow structures by varying the amount of sulfur precursor, L-cysteine. Structural analysis and electrochemical performance comparisons were conducted accordingly. Linear sweep voltammetry (LSV) revealed that the hollow-structured NiS2 catalysts exhibited improved overpotential performance. Furthermore, kinetic analysis using Tafel plots indicated enhanced hydrogen adsorption kinetics in the hollow-structured NiS2 catalysts compared to their non-hollow counterparts.