CoP nanorods decorated biomass derived N, P co-doped carbon flakes as an efficient hybrid catalyst for electrochemical hydrogen evolution

•A novel and efficient hybrid composed of CoP NRs and NPCFs was constructed.•The CoP/NPCFs hybrid catalyst exhibits efficient electrocatalytic activity for HER.•The defects and catalytic active sites were enhanced after N, P codoping.•The synergetic effect between NPCFs and CoP contributes to high catalytic activity.•This study opens a door for designing novel CoP-based HER electrocatalysts.

How to enhance the catalytic performance of electrocatalyst for the hydrogen evolution reaction (HER) is the main focus among many researches. In this work, an efficient hybrid composed of CoP nanorods (NRs) and N, P co-doped carbon flakes (NPCFs) which were synthesized by direct pyrolysis of the mixture of biomass macromolecule sodium alginate and ammonium hypophosphite was constructed. The as-synthesized CoP/NPCFs hybrid catalyst exhibits efficient electrocatalytic activity with a low onset overpotential (45 mV), small Tafel slope (67 mV dec−1), high exchange current density (1.37 × 10−3 mA cm−2), large electrochemical double-layer capacitance (9.25 mF cm−2) and good stability for HER in 0.5 M H2SO4 solution. The good HER electrocatalytic performance derived from the more defects and active sites in the catalyst as well as the strong synergetic effect between NPCFs and CoP NRs. This study opens a door for designing low-cost transition metal phosphide catalysts decorated heteroatom doped carbon materials for water splitting.

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