CoP@NRGO composite as a high-efficiency water electrolysis catalyst for hydrogen generation

Abstract It is critical for energy conversion research to seek an inexpensive and efficient electrocatalyst for the hydrogen evolution reaction (HER). Transition metal phosphides are gradually being considered as prospective catalysts to replace noble metal catalysts such as Pt. Herein, we report an easy way to synthesize cobalt phosphide nanorods grown on a nitrogen-doped reduced graphene oxide layer composite (CoP@NRGO) via hydrothermal growth and a low-temperature phosphorization process. This composite presents a marvelous performance for the HER in acid solution. It achieves a current density of 10 mA cm−2 with only a small overpotential of 90 mV, along with a Tafel slope of 87 mV·dec−1 in 0.5 M H2SO4. In addition, it has desirable long-term stability in the solution. In this work, we not only demonstrated a terrific electrocatalyst for the HER but also provid a simple preparation technique to fabricate graphene layers with other materials.