Nitrogen-, phosphorus-doped carbon–carbon nanotube CoP dodecahedra by controlling zinc content for high-performance electrocatalytic oxygen evolution

Abstract

Here, N- and P-doped carbon–carbon nanotube CoP (NPC-CNTs-CoP) nanoparticles dodecahedra are achieved by multistep calcination of the Zn-doped zeolitic imidazolate framework ZIF-67 precursor (ZnCo-ZIF). In the structures, the presence of N and P atoms, abundant CNTs and the CoP nanoparticles can enhance electrochemical activity and promote the structural stability of materials. As the temperature increases, the Zn contents gradually reduce to zero, which provides more active sites for electrochemical testing. Furthermore, the high specific surface area and microporous behavior of NPC-CNTs-CoP-9 make it excellent in electrocatalytic testing. NPC-CNTs-CoP-9 shows a low overpotential of 224 mV at 10 mA·cm−2 in 1.0 mol·L−1 KOH solution. The strategy of zeolitic imidazole framework-derived transition metal phosphides will provide a new sight for developing energy conversion materials.