Visible Light‐Assisted Photocatalytic Degradation of Tetracycline Over WS 2 Nanoislands Anchored on 3D Nitrogen and Phosphorus‐Codoped Graphene‐Based Macroarchitectures
Tajamul Shafi, Chinmayee Das, Zahoor Manzoor, Rajasekhar Balasubramanian, Brajesh Kumar Dubey, Shamik ChowdhuryABSTRACT
The increasing occurrence of pharmaceutically active compounds in aquatic environments necessitates the development of effective and sustainable water treatment technologies. In this study, a novel 3D photocatalyst, comprising tungsten disulfide (WS 2 ) nanoislands anchored on nitrogen (N) and phosphorus (P) codoped graphene frameworks (WNPGFs), was synthesized via a facile hydrothermal method. Codoping with N and P induces synergistic structural and electronic modifications within the graphene matrix, including p‐type semiconductivity, improved charge separation, and enhanced light absorption, while the integration of WS 2 provides surplus active sites for photocatalysis. As a result, the optimized WNPGF achieved 93% tetracycline degradation under visible light within 120 min. Mechanistic investigations revealed that superoxide radicals and photogenerated holes played dominant roles in the oxidative degradation pathway. Although photocatalytic activity decreased in real water matrices due to interference from competing species, WNPGF retained appreciable degradation efficiency, demonstrating its potential under environmentally relevant conditions. Phytotoxicity assays confirmed that the treated effluent was non‐toxic, supporting its potential reuse for non‐potable applications such as irrigation. Furthermore, the catalyst demonstrated excellent short‐term reusability. These findings highlight the promise of WNPGF as a practical and environmentally benign photocatalyst for the removal of antibiotic contaminants in advanced water and wastewater treatment systems.