Directional charge transfer modulation in ultrathin polyporous carbon nitride nanotubes for enhanced peroxymonosulfate activation

Abstract

Achieving enhanced degradation efficiency of the legacy pesticidal persistent organic pollutants in a photocatalysis coupling peroxymonosulfate activation (PC-PMS) system by boosting photogenerated carrier separation, remains considerable challenges. Herein, we delved into the directional charge transfer modulation of built-in electric field (BEF) within polyporous ultrathin carbon nitride nanotubes for strengthened PC-PMS mediated pesticide degradation. The ultrathin polyporous tubular nanostructure, are critical in shortening the diffusion pathways for the transport of photogenerated electron-hole pairs to the reaction interface, while simultaneously ensuring the abundant contact sites for the reaction medium. Additionally, the heptazine units containing amino groups served as oxidation centers under visible light, targeting the generation of reactive oxygen species of h+, O2•−, 1O2. While the heptazine units containing cyano groups and boron dopants acted as reduction centers, activating PMS and O2 to produce SO4•−, •OH and O2•−. The efficient generation of the radical species contributed to the ultrafast imidacloprid degradation in PC-PMS system. This study demonstrates that the combination of morphology and BEF engineering is a promising strategy for enhanced degradation efficiency of pesticide pollutants in the PC-PMS system.