Tuning the electronic configuration of Co-Nx for highly efficient H2O2 production in acidic solution

Abstract

The production of hydrogen peroxide (H2O2) through electrochemically reducing O2 in a two-electron pathway is a potential substitute for the traditional process based on anthraquinone. In this paper, F doping is carried out to prepare N and F co-doped porous carbon embedded Co nanoparticles. The electro-catalytic activity for the electrochemical production of H2O2 is systematically investigated. The composite material demonstrates exceptional electro-catalytic selectivity, reaching approximately 92.5%, and shows an ultra-high rate of producing H2O2 in 4021.4 mmol g−1 h−1 at 0.1 V versus RHE in a 0.5 M H2SO4 electrolyte. It is found that the synergetic effect of Co-Nx and F in the composite material result in its exceptional performance. Adding F atom modulates the Zeta potential of the catalyst and alters the electronic configuration around Co-Nx, creating favorable conditions for the uptake of O2 and consequently forming OOH*. Additionally, the highly electronegative F atom facilitate desorbing OOH* through electrostatic repulsion, preventing any further degradation. In a homemade electrolyzer containing 80 mg L−1 of Rh B, the H2O2 produced in situ in a 0.5 M H2SO4 electrolyte degrades up to 97.76% of Rh B in just 22.5 minutes, showcasing its potential for practical wastewater treatment applications.