Fe-Co bimetallic sulfides in-situ loading onto g-C3N4 with abundant nitrogen vacancies for peroxymonosulfate activation: Efficient atrazine degradation and radical/non-radical mechanisms

Abstract

Graphitic carbon nitride (g-C₃N₄) offers advantages such as tunable electronic structure, rich pyridinic-N content, low cost and environmental benignity, yet its intrinsic catalytic capacity for peroxymonosulfate (PMS) activation remains limited. Herein, we proposed a novel catalyst by in-situ loading Fe-Co bimetallic sulfides onto g-C₃N₄ (Fe₁Co₁@SCN) through a simple one-step pyrolysis method. Beyond the synergistic effect between the Fe-Co bimetallic sulfides, abundant nitrogen vacancies (NVs) were introduced to promote electron transfer through charge redistribution and facilitate the redox cycle of Fe-Co, driving PMS activation to generate HO^• as the primary reactive species. Through UHPLC-MS analysis and density functional theory (DFT) calculations, degradation pathways for ATZ were elucidated. Toxicity predictions, supported by mung bean hydroponics experiments, revealed a significant detoxification capability of the system. Moreover, Fe₁Co₁@SCN was integrated into a catalytic membrane reactor, maintaining over 97.6 % ATZ removal during continuous purification. This study offers valuable insights into the rational design of bimetallic catalysts for environmental remediation and underscores the potential of advanced oxidation processes in effectively degrading refractory organic contaminants.