Chemistry Department, Faculty of Science, Ain-Shams University, Abbassia, Cairo, Egypt.
Chemistry Department, Faculty of Science, Ain-Shams University, Abbassia, Cairo, Egypt; Energy Materials Laboratory (EML), School of Sciences and Engineering, The American University in Cairo, New Cairo, 11835, Egypt.
Chemosphere. 2021 Aug;277:128730. doi: 10.1016/j.chemosphere.2020.128730. Epub 2020 Nov 3.
Visible-light-driven photocatalysis is a green and efficient strategy for wastewater treatment, where graphitic carbon nitride-based semiconductors showed excellent performance in this regard. Consequently, we report on the development of a green and facile one-pot room-temperature ultrasonic route for the preparation of novel ternary nanocomposite of cadmium sulfide quantum dots (CdS QDs), zinc oxide nanoparticles (ZnO NPs), and graphitic carbon nitride nanosheets (g-CN NSs). The proposed materials had been characterized by several physicochemical techniques such as PXRD, XPS, FE-SEM, HR-TEM, PL, and DRS. The photocatalytic efficiency of the proposed photocatalysts was assessed towards the photodegradation of Rhodamine B dye as a water pollutant model using spectrophotometric measurements. The as-synthesized novel ternary nanocomposite (CdS@ZnO/g-CN) exhibited perfect photocatalytic activity, where almost complete degradation was achieved in only 2 h under UV-irradiation or 3 h under visible-irradiation. Various methods were used to elucidate the kinetics of the photocatalytic process. Moreover, CdS@ZnO/g-CN exhibited a unique synergetic performance when compared to the corresponding binary composites or the individual components. This synergetic performance could be ascribed to the perfect electronic band configuration of the three components, leading to the establishment of several combined synergetic Z-Scheme/Type-II photocatalytic heterojunctions, which is the proposed mechanism for the observed synergetic photocatalytic reactivity of the as-synthesized CdS@ZnO/g-CN nanocomposite when compared to the single and binary nanocomposite counterparts. Furthermore, the effects of both the type and concentration of various scavengers on the photocatalytic activity were assessed to investigate the most reactive species, where the reductive degradation pathway was found to be the predominant route. Finally, the photocatalytic efficiency of the as-synthesized CdS@ZnO/g-CN composite showed promising and competing results when compared to other photocatalysts reported in the literature.
可见光驱动的光催化是一种绿色高效的废水处理策略，其中基于石墨相氮化碳的半导体在这方面表现出了优异的性能。因此，我们报告了一种绿色简便的一锅室温超声法，用于制备新型硫化镉量子点 (CdS QDs)、氧化锌纳米粒子 (ZnO NPs) 和石墨相氮化碳纳米片 (g-CN NSs) 的三元纳米复合材料。所提出的材料通过几种物理化学技术进行了表征，如 PXRD、XPS、FE-SEM、HR-TEM、PL 和 DRS。通过分光光度法测量评估了所提出的光催化剂对罗丹明 B 染料作为水污染模型的光降解效率。所合成的新型三元纳米复合材料 (CdS@ZnO/g-CN) 表现出完美的光催化活性，在 UV 照射下仅 2 小时或在可见光照射下 3 小时内几乎完全降解。使用各种方法阐明了光催化过程的动力学。此外，与相应的二元复合材料或单个组件相比，CdS@ZnO/g-CN 表现出独特的协同性能。这种协同性能可以归因于三种组分的完美电子能带结构，导致建立了几个组合的协同 Z-方案/II 型光催化异质结，这是所提出的机制，用于解释与单一组分和二元纳米复合材料相比，所合成的 CdS@ZnO/g-CN 纳米复合材料观察到的协同光催化反应性。此外，评估了各种类型和浓度的猝灭剂对光催化活性的影响，以研究最活跃的物种，发现还原降解途径是主要途径。最后，与文献中报道的其他光催化剂相比，所合成的 CdS@ZnO/g-CN 复合材料的光催化效率表现出有希望和有竞争力的结果。
