High performance electrocatalysis for hydrogen evolution reaction using nickel-doped CoS2 nanostructures: experimental and DFT insights

Development of non-noble-metal electrocatalysts with high activity and durability is a competitive strategy for the practical applications of water splitting which including hydrogen evolution reaction (HER) as well as oxygen evolution reaction (OER). In this work, high-quality CoS2 ultrathin nanosheets were synthesized through a simple and efficient hydrothermal method. After merging 10% wt Ni, the bimetal catalyst (Co0.9Ni0.1S2) displays excellent catalytic activity (10 mA cm−2 at an overpotential of 156 mV and a small Tafel slope of 52 mV dec−1) as well as stability (over 3000 cycles without obvious decay) in acid condition. Based on the results of Density Functional Theory (DFT) calculations, H+ adsorbed competition, hydrogen formation energetic and kinetics are proposed to help us understand the high efficient HER process over the Co0.9Ni0.1S2 (CNS) ultrathin nanosheets.