Heterostructured CoFeP/CoP as an Electrocatalyst for Hydrogen Evolution in Alkaline Media.

Developing highly efficient and persistent transition-metal-phosphide (TMP)-based electrocatalysts is critical for the hydrogen evolution reaction (HER) via water splitting in alkaline media. Herein, we constructed a unique heterostructured CoFeP/CoP grown on a nickle foam (NF) via hydrothermal and dipping methods followed by phosphorization at different temperatures for HER. The experimental results exhibit that the HER activity of CoFeP/CoP-400 is accelerated after the construction of heterostructures. The unique heterostructure provides plentiful active sites and a large surface area, which are beneficial for HER in 1.0 M KOH. CoFeP/CoP-400 displays a small overpotential of 78 mV at a current density of 10 mA cm -2 and a smaller Tafel slope of 55.5 mV dec -1 . Moreover, CoFeP/CoP-400 shows excellent stability with a long-term operating time of 12 h. This work provides an effective method for the construction of TMPs with heterostructures for promoting energy conversion.