Iron molybdenum selenide supported on reduced graphene oxide as an efficient hydrogen electrocatalyst in acidic and alkaline media

It is of great significance to develop inexpensive and high-efficiency electrocatalysts for the hydrogen evolution reaction (HER). In this work, we synthesized iron molybdenum selenide (FeSe2-MoSe2) loaded on reduced graphene oxide (FeSe2-MoSe2/rGO) by a one-step hydrothermal method. We further optimized the Fe/Mo ratio and determined the best ratio to be 1-1. In acidic (or alkaline) solution, the optimized FeSe2-MoSe2(1-1)/rGO has a small Tafel slope of 55 (or 80) mV dec−1 and needs an overpotential of 101 (or 178) mV to achieve 10 mA cm−2. These good properties are mainly due to the structure of bimetallic selenides combining rGO. Moreover, rGO enhances the electrical conductivity. Furthermore, the synergistic effect between FeSe2-MoSe2(1-1) and rGO results in better HER performance. Density functional theory (DFT) calculation proves that FeSe2-MoSe2(1-1)/rGO has a small work function. Based on our reasonable design and analysis, FeSe2-MoSe2(1-1)/rGO is expected to be an efficient and robust catalyst for large-scale applications.