Ag nanoparticle-mediated LSPR effect and electron transfer for enhanced oxidative degradation process of g-C3N5 nanoflowers

The design of photocatalytic system with broad-spectrum response to sunlight and rapid electron transfer is critical for efficient destruction of diverse contaminants in various environmental situations. Herein, self-assembled supramolecular strategy was employed to anchor Ag nanoparticles on the nanoflower-like g-C₃N₅ surface to construct Schottky-type catalyst (ACN-1) for efficient degradation of organic contaminants. The localized surface plasmon resonance (LSPR) effect significantly improves photocatalytic activity of materials by boosting rapid transfer of interlayer energy and photogenerated electrons and extending the absorption edge of catalysts into near-infrared light region. In actual water samples, ACN-1 entirely eliminated tetracycline (k = 1.0787 min⁻¹) within 40 min and maintained high degradation rate (more than 80 %) under various water quality parameters. Furthermore, ACN-1 demonstrated remarkable suitability to microcystin-LR (98.9 %, k = 0.08098 min⁻¹), sulfamethoxazole (81.2 %, k = 0.02984 min⁻¹), and methylene blue (91.4 %, k = 0.04072 min⁻¹). Quenching experiments and ESR tests showed that main active species in system were ¹O₂, •O₂⁻, and h⁺. Finally, five photodegradation pathways and 26 intermediates of TC were elucidated by combining ESR signals, LC-MS and Fukui index. After photodegradation treatment, the toxicity of solution was drastically reduced and the mineralization reached 62.48 %. This study provides new insights into the design and interaction mechanisms of novel g-C₃N₅-based catalysts and effectively contributes to remediation strategies for emerging pollutants in water.