Department of Biotechnology, Thapar Institute of Engineering and Technology, Bhadson Road, Patiala, 147004, Punjab, India.
Department of Agriculture and Environmental Sciences, National Institute of Food Technology Entrepreneurship and Management, Kundli, Sonepat, Haryana, 131028, India.
Environ Sci Pollut Res Int. 2024 Jul;31(35):47991-48013. doi: 10.1007/s11356-024-34080-5. Epub 2024 Jul 17.
This study investigates the photocatalytic degradation of norfloxacin (NFX) utilizing Fe-doped TiO nanocomposite under natural sunlight. TiO-based photocatalysts were synthesized using chemical precipitation varying Fe-dopant concentration and characterized in detail. Theoretical modelling, centred on density functional theory (DFT), elucidated that Fe ions within the TiO lattice are effectively confined, thereby narrowing the wide band gap of TiO. The findings strongly support that Fe ions augmented the photocatalytic activity of TiO by facilitating an intermediate interfacial route for electron and hole transfer, particularly up to an optimal dopant concentration of 1.5 M%. Subsequently, a three-level Box-Behnken design (BBD) was developed to determine the initial pH, optimal catalyst concentration, and drug dosage. High-performance liquid chromatography-mass spectrometry (HPLC-MS) was employed to identify reaction intermediates, thereby establishing a potential degradation pathway. Notably, sustained recyclability was achieved, with 82% degradation efficiency maintained over five cycles. Additionally, the toxicity of degradation intermediates was evaluated through bacterial and phytotoxicity tests, affirming the environmental safety of treated water. In vitro toxicity of the nanomaterial was also examined, emphasizing its environmental implications. Scavenger experiments revealed that hole and hydroxyl radicals were the primary active species in Fe-TiO-based photocatalysis. Furthermore, the antibacterial potential of the synthesized catalyst was assessed using Escherichia coli and Staphylococcus aureus to observe their respective antibacterial responses.
本研究利用 Fe 掺杂 TiO 纳米复合材料在自然光下研究诺氟沙星（NFX）的光催化降解。采用化学沉淀法合成了 TiO 基光催化剂，改变了 Fe 掺杂浓度，并进行了详细的表征。基于密度泛函理论（DFT）的理论建模表明，Fe 离子有效地限制在 TiO 晶格内，从而缩小了 TiO 的宽带隙。研究结果强烈支持 Fe 离子通过促进电子和空穴转移的中间界面途径来提高 TiO 的光催化活性，特别是在最佳掺杂浓度为 1.5 M%时。随后，开发了三水平 Box-Behnken 设计（BBD）来确定初始 pH 值、最佳催化剂浓度和药物剂量。采用高效液相色谱-质谱（HPLC-MS）来鉴定反应中间体，从而建立了潜在的降解途径。值得注意的是，该催化剂具有良好的循环稳定性，经过五次循环后仍保持 82%的降解效率。此外，通过细菌和植物毒性测试评估了降解中间体的毒性，证实了处理水的环境安全性。还对纳米材料的体外毒性进行了评估，强调了其环境影响。清除实验表明，空穴和羟基自由基是基于 Fe-TiO 的光催化中的主要活性物质。此外，还利用大肠杆菌和金黄色葡萄球菌评估了合成催化剂的抗菌潜力，观察它们各自的抗菌反应。
