Nanostructured MoSe₂/NiSe₂ Electrocatalystswith Heterojunctions for Hydrogen Evolution Coupling Urea Oxidation

Abstract

Developing highly efficient and low-cost hydrogen evolution reaction (HER) electrocatalysts is an urgent and important task for development of green water electrolysis hydrogen production technology. In this work, the nanostructured MoSe₂/NiSe₂ electrocatalyst with heterojunctions is constructed by a two-step hydrothermal method for HER coupling urea oxidation reaction (UOR). The presence of heterojunctions accelerates the charge transfer and enhances the conductivity of electrocatalysts; thus, the as-prepared nanostructured MoSe₂/NiSe₂ exhibits bifunctional electrocatalytic activity. Low overpotentials of 79 and 120 mV are required to achieve 10 mA cm^–2 current density for the HER and UOR, respectively. For the two-electrode urea electrolysis containing 1 M KOH and 0.5 M urea, a voltage of only 1.47 V is required to deliver the current density of 10 mA cm^–2. Density functional theory (DFT) calculation results show that the MoSe₂/NiSe₂ electrocatalyst can optimize the adsorption of H* and improve the HER activity because of the existence of the heterostructure. This work provides a promising potential for designing energy-saving hydrogen evolution catalysts with alternative electrode reactions.