Solar light induced photocatalytic oxidative degradation of organic pollutants and bacterial inactivation is an attractive strategy for water purification. Current work is on the use of silver/silver (II) oxide (Ag/AgO) grown insitu on the surface of graphitic carbon nitride (g-C₃N₄) as photocatalyst for the effective utilization of solar radiation, as this system can have extended visible light absorption due to the surface plasmon resonance (SPR) phenomenon of metallic silver. Ag/AgO loaded g-C₃N₄ microspheres (Ag/AgO/g-CNMS) were prepared by a facile thermal heating method. The structural and morphological analysis confirmed the existence of metallic Ag and AgO in mixed phase on the surface of carbon nitride. This composite exhibits significant visible light absorption and a reduction in the bandgap compared to g-C₃N₄ due to the SPR exhibited by the metallic silver and lower bandgap of AgO. Photoelectrochemical studies suggest lower charge transfer resistance and better capacitive behaviour for the composite compared to g-C₃N₄. The composite catalyst shows improved photocatalytic performance for the degradation of acid violet-7 dye (AV-7). Besides, it is found to possess significant bactericidal property for the destruction of E. coli bacteria. This is the first report on the enhanced photocatalytic activity of a silver-g-C₃N₄ system comprising of silver (II) oxide. The present system containing silver (II) oxide shows significantly improved photocatalytic activity and stability compared to the Ag/Ag₂O/g-C₃N₄ with silver (I) oxide reported earlier. The improved performance of the composite is attributed to the increased optical absorption properties and better separation of photogenerated charge carriers. The reactive oxidative species responsible for the degradation reaction is identified and a plausible degradation pathway for the AV7 dye is presented. Furthermore, this catalyst is found to be stable and does not show any decrease in the photocatalytic activity even after several repeated cycles.

中文翻译：

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载银/氧化银（Ag / AgO）的石墨氮化碳微球：一种有效的可见光活性光催化剂，可降解酸性染料和使细菌失活

太阳光诱导的有机污染物的光催化氧化降解和细菌的灭活是用于水净化的有吸引力的策略。当前的工作是使用就地生长在石墨氮化碳（gC ₃ N ₄）表面上的银/银（II）氧化物（Ag / AgO ）作为光催化剂，以有效利用太阳辐射，因为该系统可以扩展金属银的表面等离振子共振（SPR）现象引起的可见光吸收。载有Ag / AgO的gC ₃ N ₄微球（Ag / AgO / g-CNMS）通过简便的热加热方法制备。结构和形态分析证实了在氮化碳表面上存在混合相中的金属Ag和AgO。与gC ₃ N ₄相比，该复合材料表现出显着的可见光吸收并减少了带隙，这是由于金属银和AgO的较低带隙表现出的SPR所致。光电化学研究表明，与gC ₃ N ₄相比，复合材料具有更低的电荷转移电阻和更好的电容性能。该复合催化剂对酸性紫7染料（AV-7）的降解显示出改进的光催化性能。此外，发现其具有破坏大肠杆菌的显着的杀菌性能。这是关于包括氧化银（II）的银-gC ₃ N ₄体系的增强的光催化活性的首次报道。与Ag / Ag ₂ O / gC ₃ N ₄相比，本发明的含氧化银（II）的体系显示出显着改善的光催化活性和稳定性。与较早报道的氧化银（I）。复合材料性能的提高归因于增加的光吸收性能和光生载流子的更好分离。确定了负责降解反应的反应性氧化物质，并提出了AV7染料的合理降解途径。此外，发现该催化剂是稳定的，并且即使经过多次重复循环也不会显示出光催化活性的任何降低。