Ni, Zn Co-doping ZIF-67-derived electrocatalyst based on CNT film for efficient overall water splitting

Abstract

Water electrolysis has been acknowledged as a renewable, scalable, and effective way of producing hydrogen. However, for water splitting, efficient and noble metal-free electrocatalysts were lacking. Here, a Co–Ni–Zn porous three-dimension N-doped carbonization structure on the carbon nanotube film (CNTF) was synthesized through a metal organic frameworks (MOFs) annealing procedure. The porous morphology, caused by the evaporation of zinc at high temperatures, enhances the interaction between the catalysts and electrolyte, and the self-supporting structure minimizes the contact resistance between the catalysts and the substrate, which reduces obstructions during current flow. More active sites, multiple mesopores, and high conductivity are all features of this composite structure. It can achieve a small overpotential of 112 mV and 270 mV at a current density of 10 mA cm−2, respectively, for hydrogen and oxygen evolution reactions (HER and OER). At a current density of 10 mA cm−2, the Co–Ni–Zn/NCNTF has an external voltage of 1.58 V and is very durable for overall water splitting.