In situ electrochemical construction of Co/CoP crystalline-amorphous hetero-phase catalysts for highly efficient electrocatalytic hydrogen evolution

Abstract

Herein we develop a facile, one-step electrochemical approach for the in situ construction of a Co/CoP crystalline-amorphous hetero-phase catalyst towards the hydrogen evolution reaction (HER). The unique catalyst demonstrates a low overpotential of 83 mV at 10 mA cm⁻² with a small Tafel slope of 55.3 mV dec⁻¹ in 1.0 M KOH. The Co/CoP crystalline-amorphous hetero-phase is highly conducive to regulating the Co–P electronic structure and weakening the H atom adsorption, thus markedly boosting the HER performance. This work offers an innovative strategy to develop a highly efficient transition metal phosphide electrocatalyst with a novel structure.