Nanoflower-like Fe-doped CoP as highly efficient catalyst for alkaline hydrogen evolution reaction

Abstract

Transition metal phosphides (TMPs) have drawn much interest as a promising electrocatalyst with outstanding physicochemical properties. However, limited active sites and sluggish kinetics greatly limit their widespread applications. Herein, a highly efficient nanoflower-like TMPs of Fe-doped CoP catalyst is tactfully prepared. Electrochemical experiments indicate that the Fe-doped CoP catalyst with 30 min exchange duration time (FeCoP/NF-30) exhibits an extremely low overpotential of only 66.60 mV to achieve a current density of 10 mA cm⁻², a Tafel slope as low as 48.34 mV dec⁻¹ and a large electrochemical active area of 32.32 mF cm⁻² in alkaline solution. The enhanced hydrogen-evolution performance of FeCoP/NF-30 is attributed to the increased active sites and decreased crystalline feature, which is beneficial to adsorbing or desorbing reaction intermediates. In addition, an increased electron density around Co element is observed, which also can promote HER performance. This work not only provides a facile strategy for developing efficient CoP electrocatalysts but also promotes fundamental studies on catalyst design for electrocatalysis and beyond.