CoP nanoparticles embedded in N-doped carbon for highly efficient oxygen evolution reaction electrocatalysis

•A novel 2D supermolecule precursor (Co-MPA) was obtained by the self-assembly.•CoP was obtained by in situ phosphating during the calcination of Co-MPA.•CoP possesses a small size of 18 nm due to the encapsulated by N-doped C layer.•The CoP/N-CNT catalyst exhibits efficient and stable catalytic performance in OER. Development of high-activity and low-cost electrocatalysts is significant to enhance the low-kinetic process of oxygen evolution reaction (OER). In this paper, we utilized the self-assembly between melamine, phytic acid and cobalt ions to obtain two-dimensional Co-MPA. Subsequently, in situ phosphating of cobalt ions to obtain CoP/N-CNT was achieved by the pyrolytic of Co-MPA. The small size of CoP (∼18 nm) and the N-doped carbon material endowed CoP/N-CNT with excellent OER electrocatalytic activity, which delivered an overpotential of 330 mV to drive a current density of 10 mA cm−2. Moreover, the TOF value of CoP/N-CNT catalyst is 4.6 times higher than the commercial RuO2 catalyst (at the overpotential of 480 mV), providing it as a promising electrocatalyst for OER.