Metal phosphide catalysts anchored on metal-caged graphitic carbon towards efficient and durable hydrogen evolution electrocatalysis

Developing cost-effective and stable electrocatalysts towards hydrogen evolution reaction (HER) is important for the conversion of renewable energy via electrocatalytic water splitting reaction. Herein, we present a simple and general strategy for the preparation of a series of metal (M: Fe, Co and Ni) phosphide catalysts that were anchored on metal-caged carbon matrix. In the first step, metal-grafted carbon precursors (M/M@NC) were rationally synthesized through metal-catalyzed growth process. Following phosphorization treatment transformed the metal precursors to metal phosphides (MP/M@NC) with the inheritance of the strong catalyst-support connection, which leads to efficient charge transport and prevents the detachment of the catalysts from the support. Benefitting from several structural advantages including high dispersability of active sites, good conductivity and strong interfacial interaction, the as-prepared MP/M@NC catalysts show high performance for HER in acidic solution. In particular, the FeP/Fe@NC exhibits extremely low overpotentials of -49 and -130 mV for achieving current densities of -10 and -100 mA cm(-2), respectively, and remarkable long-term durability, which highlights the importance of rational catalyst/support design towards efficient and stable electrocatalysis.