Self-supported rectangular CoP nanosheet arrays grown on a carbon cloth as an efficient electrocatalyst for the hydrogen evolution reaction over a variety of pH values

Recent research suggests that transition metal phosphides (TMPs) are one of the most promising nobel-metal-free electrocatalysts for catalyzing the hydrogen evolution reaction. In this study, we report rectangular CoP nanosheet (NS) arrays on carbon cloth (CoP NS/CC) via a concise two-step synthetic method. The 3D rectangular CoP NS/CC with a three-dimensional porous and self-supported structure was fabricated via a hydrothermal method, followed by a low-temperature phosphidation treatment. Such 3D rectangular CoP NS/CC, as an HER electrocatalyst in acidic solution, exhibited high activity, good stability, and nearly 100% Faradaic efficiency (FE). The electrocatalyst requires an overpotential of 92, 112 and 195 mV to achieve current densities of 10, 20 and 100 mA cm−2, respectively, and maintain its catalytic stability for more than 50 h. In addition, the electrocatalyst works well in a neutral environment.