Waste biomass-derived N, P co-doping carbon aerogel-coated CoxFe1−xP with modulated electron density for efficient electrooxidation of contaminants

Abstract

Developing low-cost, green, high-performing electrode materials to address environmental pollutants and the energy crisis is significant but challenging. Herein, the bimetallic iron cobalt phosphide coated in waste biomass-derived N, P co-doping carbon (CoxFe1−xP@NPC) is constructed. Furthermore, the active site density and the water decomposition energy barrier of surface-coated NPC are modulated by optimizing the electronic structure of CoxFe1−xP via doping engineering. The Fe-modulated CoxFe1−xP@NPC exhibits a hierarchical porous self-supporting structure and excellent physical & chemical properties with excellent electrooxidation performance, achieving over 95% removal of TCH within 60 min. The density functional theory (DFT) calculations further confirms that N carries more positive charge and P carries more negative charge in the NPC of CoxFe1−xP@NPC with Fe modulation, which can promote the adsorption and dissociation of water molecules. Of note, Co0.75Fe025P@NPC displays a low water dissociation energy barrier to produce ·OH and a high energy barrier to produce O2 than its counterparts. This study offers new insight into controllable modulation of biomass carbon-based composite electrode catalytic activity for high-efficiency degradation of contaminants.