Constructed Interfacial Oxygen‐Bridge Chemical Bonding in Core‐Shell Transition Metal Phosphides/Carbon Hybrid Boosting Oxygen Evolution Reaction

Abstract A designed structure which CoP nanoparticles (NPs) ingeniously connected with graphene‐like carbon layer via in‐situ generated interfacial oxygen‐bridge chemical bonding was achieved by a mild phosphorization treatment. The results proved that the presence of phosphorus vacancies is a crucial factor enabling formation of Co−O−C bonds. The direct coupling of edge Co of CoP with the oxygen from functional groups on the carbon layer was proposed. As a catalyst for electrocatalytic water splitting, the manufactured Fe 2 O 3 @C@CoP core‐shell structure manifested a low overpotential of 230 mV, a low Tafel slope of 55 mV dec −1 , and long‐term stability. Density functional theory calculations verified that the Co−O−C bond played a critical role in decreasing the thermodynamic energy barrier of reaction rate‐determining step for the oxygen evolution reaction (OER). This synthetic route might be extended to construct metal−O−C bonds in other transition metal phosphides (or selenides, sulfides)/carbon composites for highly efficient OER catalysts.