Electron Transfer Induced by Carbon Nitride/Boron Nitride Heterojunction for Boosted Superoxide Radical Generation from Molecular Oxygen in Pollutant Removal

This study systematically elucidates the molecular oxygen activation mechanisms and selective ROS generation pathways mediated by carbon nitride/boron nitride (CN-BN) heterojunction catalysts. Leveraging the similar electronic structures of carbon and boron, DFT calculations revealed that the CN-BN heterojunction enhances hydrogen peroxide (H₂O₂) and sulfamethoxazole (SMX) adsorption via optimized interfacial electron transfer. A series of graphene-like CN-BN heterostructures were successfully fabricated via a facile single-step pyrolysis protocol. Electron spin resonance (ESR) and probe experiments were employed to quantify the concentration of ROS, revealing that O₂^•- contributed to 91.05% of the ROS involved in the degradation of target pollutant. Synergistic experimental and computational analyses demonstrated that strengthened internal electric fields at the heterojunction interface synergistically enhance contaminant adsorption and charge transfer kinetics, thereby accelerating degradation processes. These findings establish fundamental guidelines for designing metal-free electrocatalytic systems and advancing organic pollutant remediation technologies.