Tailoring of cobalt phosphide anchored nitrogen and sulfur co-doped three dimensional graphene hybrid: Boosted electrocatalytic performance towards hydrogen evolution reaction

Abstract

The tailoring of a high-performance, low-cost hybrid electrocatalysts with excellent stability in acidic media for hydrogen evolution reaction (HER) has gain paramount importance. Herein, the cobalt phosphide decorated nitrogen and sulfur co-doped three dimensional graphene (CoP@N,S-3D-GN) electrocatalyst was synthesized via a simple two step production pathway including hydrothermal self-assembly and low-temperature phosphidation. Compared both with CoP-anchored 3D-GN (CoP@3D-GN) and N,S-co-doped 3D-GN (N,S-3D-GN) samples, profiting from the synergistic merits of co-doping and metal phosphide, CoP@N,S-3D-GN delivers boosted electrocatalytic activity towards HER with an overpotential of only 118 mV at 10 mA.cm(-2), a Tafel slope of 50 mV.dec(-1) and an exchange current density of 2.2 x 10(-2) mA.cm(-2). Furthermore, it preserves its electrocatalytic activity for both after 1000 cyclic voltammetry cycles at 100 mV.s(-1) potential scan rate and at least 50 h under 120 mV overpotential. This work provides rational route for engineering of metal phosphides anchored 3D-graphene hybrid electrocatalysts to boost the HER catalytic performance. (C) 2021 Elsevier Ltd. All rights reserved.