N, P co-doping Co9S8/NC for enhanced the Electrocatalytic water splitting in all-pH

Abstract

Hydrogen energy represents a form of green energy, and the electrolysis of water for hydrogen production is recognized as an efficient method. Current research is primarily focused on the development of catalysts that are both efficient and stable, particularly those capable of functioning consistently across the entire pH spectrum. In this work, Co₉S₈/NC co doped with N and P was successfully synthesized through a series of sulfurization, calcination, and phosphating operations using dual ligand Co-ZIF as the precursor. By coating a carbon layer and co doping with nitrogen and phosphorus, the catalytic performance and stability of hydrogen evolution reaction (HER) were significantly improved over the entire pH range. At a fixed current density of 10 mA cm⁻², the overpotential of HER was measured at voltages of 136, 96, and 194 mV in three different pH solutions. Furthermore, the electrocatalyst exhibits remarkable electrochemical stability over extended periods. After 20 h or 2000 cycles of testing, the catalytic activity did not show a significant decrease across the entire pH range, but rather exhibited a relatively sustained constant.