In situ coupled MoO3 with CoP/rGO to construct three-dimensional self-supported catalyst for highly efficient alkaline hydrogen evolution reaction

Abstract In order to solve the crisis of energy depletion and protect the beautiful natural environment, the development of efficient, cost-effective and stable hydrogen evolution reaction (HER) electrocatalyst has attracted great attention, but it is still an urgent challenge to fabricate an abundant and low cost electrocatalyst. In this article, a novel HER catalyst with heterogeneous structure interfaces was in situ synthesized by multi-step electrodeposition method, and the mechanism of the enhancement of its electrocatalytic activity was elucidated by the combination of density functional theory (DFT) calculation and multi-characterizations. The initial overpotential is only 83 mV and the Tafel slope is only 58.5 mV/dec, which is better than most of other reported CoP-based electrocatalyst. At the meantime, DFT calculations show that the incorporation of MoO3 and rGO leads to electron redistribution among different components, which ensures efficient adsorption and activation of H2O molecules and hydrogen atoms. Therefore, this work will contribute to the understanding of the mechanisms associated with heterojunctions and provide guidance for the rational design of a hybrid catalyst.