Fabrication of Cerium-Doped CoMoP/MoP@C Heterogeneous Nanorods with High Performance for Overall Water Splitting

Doping rare-earth metals or introducing carbon into transition metal phosphides (TMPs) can promote the property and stability of water electrolysis. An original composite nanostructure, cerium-doped and carbon-coated CoMoO4 (Ce-doped CoMoO4@C), was obtained by a simple hydrothermal and annealing process successively. Subsequently, chemical vapor deposition (CVD) was adopted to synthesize carbon-coated and cerium-doped CoMoP/MoP (Ce-doped CoMoP/MoP@C) with diammonium hydrogen phosphate as the phosphorus source. Ce-doped CoMoP/MoP@C displayed superb bifunctional HER and OER catalytic performance under alkaline conditions. The overpotential η10, Tafel slope, and double-layer capacitance (C dl) for the OER were 287.0 mV, 74.4 mV dec–1, and 10.44 mF cm–2, while for the HER, these values were 188.0 mV, 72.2 mV dec–1, and 33.00 mF cm–2, respectively. Meanwhile, only 1.59 V (@10 mA cm–2) was needed to drive the entire water splitting. In addition, there was no apparent attenuation after electrolytic catalysis for 12 h continuously. The superb performance and endurance gave credit to the cooperative effect between carbon materials and metal phosphides and the optimized electronic structure by the incorporation of the Ce element.