Constructed Interfacial Oxygen-bridge Chemical Bonding in Core-Shell Transition Metal Phosphides/Carbon Hybrid Boosting Oxygen Evolution Reaction.

A designed structure which CoP nanoparticles (NPs) ingenious connected with graphene-like carbon layer via in-situ generated interfacial oxygen-bridge chemical bonding is achieved by a governable mild phosphorization treatment. The results give an explicit proof that the presence of phosphorus vacancy are crucial factors enabling formation of Co-O-C bond. The direct coupling of edge Co of CoP with the oxygen from functional groups on carbon layer is proposed. As a catalyst for electrocatalytic water splitting, the manufactured Fe 2 O 3 @C@CoP core-shell structure manifests a low overpotential of 230 mV, a low Tafel slope of 55 mV/dec and long-term stability. Density functional theory (DFT) calculations verified Co-O-C bond played a critical role in decreasing the thermodynamic energy barrier of reaction rate-determining step for OER. This synthetic route might be extended to construct metal-O-C bonds in other transition metal phosphides (or selenides, sulfides)/carbon composite for high-efficient OER catalysts.