Department of Chemistry, Shahreza Branch, Islamic Azad University, P.O. Box 311-86145, Shahreza, Isfahan, Iran.
Chemosphere. 2023 Sep;334:139019. doi: 10.1016/j.chemosphere.2023.139019. Epub 2023 May 24.
A critical, challenging environmental issue is explored pollution of water supplies by discharging industrial/pharmaceutical/hospital/urban wastewaters into the aquatic environment. These needs introducing/developing novel photocatalysts/adsorbents/procedures for removing or mineralizing various pollutants in wastewater before discharging them into marine environments. Further, optimizing conditions to achieve the highest removal efficiency is an important issue. In this study, CaTiO/g-CN (CTCN) heterostructure was synthesized and characterized by some identification techniques. The simultaneous interaction effects of the experimental variables on the boosted photocatalytic activity of CTCN in the degradation of gemifloxcacin (GMF) were studied in RSM design. The optimal values for four parameters were: catalyst dosage: 0.63 g L, pH: 6.7, C: 1 mg L, and irradiation time: 27.5 min, with approximately 78.2% of degradation efficiency. The quenching effects of the scavenging agents were studied to show the reactive species' relative importance in GMF photodegradation. The results illustrate that the reactive OH plays a significant role, and the electron plays a minor role in the degradation process. The direct Z-scheme mechanism better described the photodegradation mechanism due to the great oxidative and reductive abilities of prepared composite photocatalysts. This mechanism is an approach to efficiently separating photogenerated charge carriers and improving the CaTiO/g-CN composite photocatalyst activity. The COD has been performed to study the details of the mineralization of GMF. The pseudo-first-order rat (from the Hinshelwood model) constants of 0.046 min (t = 15.1 min) and 0.048 min (t = 14.4 min) were respectively obtained from the GMF photodegradation data and COD results. The prepared photocatalyst retained its activity after five reusing runs.
一个具有挑战性的关键环境问题是工业/制药/医院/城市废水排放到水生环境中对供水的污染。这些需要引入/开发新型光催化剂/吸附剂/程序，用于去除或矿化废水中的各种污染物，然后再将其排放到海洋环境中。此外，优化条件以达到最高的去除效率是一个重要的问题。在本研究中，通过一些鉴定技术合成并表征了 CaTiO/g-CN（CTCN）异质结构。在 RSM 设计中研究了实验变量对 CTCN 在 gemifloxcacin（GMF）降解中增强光催化活性的同时相互作用效应。四个参数的最佳值为：催化剂用量：0.63 g L、pH：6.7、C：1 mg L 和辐照时间：27.5 min，降解效率约为 78.2%。通过研究猝灭剂的猝灭效应，表明在 GMF 光降解过程中活性物质的相对重要性。结果表明，在降解过程中，OH 发挥了重要作用，电子发挥了次要作用。由于制备的复合光催化剂具有较强的氧化还原能力，直接 Z 型机制更好地描述了光降解机制。这种机制是一种有效分离光生载流子并提高 CaTiO/g-CN 复合光催化剂活性的方法。通过 COD 研究了 GMF 矿化的详细情况。从 Hinshelwood 模型获得的 GMF 光降解数据和 COD 结果的伪一级速率常数（t=15.1 min 时为 0.046 min，t=14.4 min 时为 0.048 min）分别为 0.046 min（t=15.1 min）和 0.048 min（t=14.4 min）。制备的光催化剂在五次重复使用后保持其活性。
