Department of Biochemistry, SP College, Cluster University Srinagar, Srinagar, J&K, India.
Department of Chemical Engineering, National Institute of Technology, Srinagar, J&K, India.
Environ Sci Pollut Res Int. 2023 Sep;30(41):93916-93933. doi: 10.1007/s11356-023-28928-5. Epub 2023 Jul 31.
Photocatalytic degradation of pharmaceutical residues through natural solar radiation represents a green and economical treatment process. In this work, ultrasonically assisted hydrothermal synthesis of WO-TiO nanocomposite was carried out at 140-150 °C for 5 h and calcinated at 600 °C. The structural and optical properties of the synthesized material were investigated using techniques like XRD, FESEM/EDX, HRTEM, BET surface area, UV-DRS optical analysis, and photocurrent response. The band gap of TiO was successfully reduced from 3.0 to 2.54 eV and thus making it effective under solar light. Complete degradation of paracetamol (50 ppm and natural pH of 6.5) was achieved in 3.5 h under natural sunlight at catalyst dose of 0.5 g/l. The extent of mineralization was evaluated by measuring the COD reduction. Based on the degradation products identified by GC-MS/LC-TOF-MS, the degradation process under natural solar-light could be interpreted to initiate through OH radical species. The toxicity removal of the treated paracetamol solution under natural solar-light was evaluated by the seed germination test using Spinacia oleracea seeds and exhibited 66.70% seed germination, confirming the reduction in toxicity. The enhanced photocatalytic efficiency of the nanocomposite is attributed to the higher surface area, low rutile content, lower band gap, and incorporation of WO, which led to an extended absorption range and a slower rate of electron-hole recombination. The technical insights presented in this research offer a feasible approach for utilizing natural solar light driven photocatalysis for wastewater treatment in an efficient and sustainable way. The proposed degradation pathway, and seed germination test (toxicity removal) of the treated paracetamol solution under natural sunlight, has not been previously evaluated.
通过自然太阳辐射的光催化降解处理药物残留代表了一种绿色、经济的处理工艺。在这项工作中，在 140-150°C 下通过超声辅助水热合成法制备 WO-TiO 纳米复合材料，并在 600°C 下煅烧。使用 XRD、FESEM/EDX、HRTEM、BET 比表面积、UV-DRS 光学分析和光电流响应等技术对合成材料的结构和光学性质进行了研究。TiO 的带隙成功地从 3.0 降低到 2.54 eV，从而使其在太阳光下有效。在自然阳光下，在催化剂剂量为 0.5 g/l 时，在 3.5 小时内即可完全降解 50 ppm 的扑热息痛（自然 pH 值为 6.5）。通过测量 COD 减少量来评估矿化程度。根据 GC-MS/LC-TOF-MS 鉴定的降解产物，可以推断在自然太阳光下的降解过程是通过 OH 自由基引发的。通过使用菠菜种子进行自然太阳光下处理的扑热息痛溶液的毒性去除评估，种子发芽率为 66.70%，证实了毒性的降低。纳米复合材料的光催化效率提高归因于更高的比表面积、更低的锐钛矿含量、更低的带隙以及 WO 的掺入，这导致了吸收范围的扩展和电子-空穴复合的速度减慢。本研究中提出的技术见解为利用自然太阳光驱动光催化技术以高效和可持续的方式处理废水提供了一种可行的方法。在自然阳光下，该方法还提出了降解途径和处理后扑热息痛溶液的种子发芽测试（毒性去除），这在以前的研究中尚未得到评估。
