A self-supported NiMoS4 nanoarray as an efficient 3D cathode for the alkaline hydrogen evolution reaction

Abstract

Developing non-noble-metal hydrogen evolution reaction electrocatalysts with high activity is critical for future renewable energy systems. Here we describe the development of a self-supported NiMoS₄ nanosheet array on Ti mesh (NiMoS₄/Ti) through a facile two-step hydrothermal strategy. As a 3D nanoarray electrode for electrochemical hydrogen evolution, NiMoS₄/Ti shows exceptionally high catalytic activity and strong durability in 0.1 M KOH (pH: 13). It needs overpotentials of only 194 and 263 mV to drive geometrical catalytic current densities of 10 and 50 mA cm⁻², respectively. Moreover, such a catalyst also demonstrates superior long-term stability with a high turnover frequency of 0.75 mol H₂ s⁻¹ at an overpotential of 148 mV. Density functional theory calculations suggest a more favorable hydrogen adsorption free energy on the NiMoS₄ surface.