Research Group in Advanced Oxidation Processes (AdOx), Department of Chemical Engineering, Escola Politécnica, University of São Paulo, Av. Prof. Luciano Gualberto, tr. 3, São Paulo, SP, 380, Brazil.
Department of Metallurgical and Materials Engineering, Escola Politécnica, University of São Paulo, Av. Prof. Luciano Gualberto, tr. 3, São Paulo, SP, 380, Brazil.
Environ Sci Pollut Res Int. 2022 Jun;29(28):42215-42230. doi: 10.1007/s11356-021-16718-w. Epub 2021 Oct 10.
Catalyst samples based on SiO-supported TiO were prepared with the incorporation of Ag (metal), S (nonmetal), and ZnO@S (semiconductor and nonmetal). The materials were evaluated regarding their morphological, optical, and crystalline properties as well as their photoactivity under visible and ultraviolet light toward the degradation rate of a model emerging pollutant, acetaminophen (ACT). All modified materials exhibited improved performance over the undoped catalyst. The Ag-doped catalyst achieved the largest degradation under visible radiation (about 30% in 120 min), whereas under ultraviolet irradiation, the ZnO@S-doped sample exhibited the best performance (about 62% in 120 min). A Doehlert design was carried out to evaluate the influence of pH and temperature on the photoactivity of Ag-TiO/SiO. In addition, the role of each reactive species in the photodegradation reaction was investigated by radical scavenger experiments, and the superoxide radical anion O was shown to be the predominant reactive species. The stability of the Ag-TiO/SiO material under ultraviolet and visible light was confirmed after five successive operation cycles, showing a reasonable (about 50%) loss of activity under visible irradiation and a slight improvement (about 13%) under UV light, as a result of the photo-reduction of Ag. Lastly, the effect of the initial pollutant concentration showed that ACT degradation using Ag-TiO/SiO follows the Langmuir-Hinshelwood kinetics, with intrinsic reaction rate k = 2.71 × 10 mmol L min under visible-light radiation.
基于 SiO2 负载 TiO2 的催化剂样品通过掺入 Ag（金属）、S（非金属）和 ZnO@S（半导体和非金属）制备而成。评估了这些材料的形貌、光学和晶体性质以及在可见光和紫外光下对模型新兴污染物扑热息痛（ACT）的光催化活性。所有改性材料的性能均优于未掺杂的催化剂。Ag 掺杂的催化剂在可见光辐射下表现出最大的降解效果（120 分钟内约 30%），而在紫外光照射下，ZnO@S 掺杂的样品表现出最佳性能（120 分钟内约 62%）。进行了 Doehlert 设计以评估 pH 和温度对 Ag-TiO/SiO 光催化活性的影响。此外，通过自由基清除剂实验研究了光降解反应中每种活性物质的作用，结果表明超氧自由基阴离子 O 是主要的活性物质。Ag-TiO/SiO 材料在紫外光和可见光下的稳定性在五次连续操作循环后得到了证实，在可见光照射下活性损失约为 50%，在紫外光下略有提高（约 13%），这是由于 Ag 的光还原作用。最后，初始污染物浓度的影响表明，Ag-TiO/SiO 用于扑热息痛的降解遵循 Langmuir-Hinshelwood 动力学，在可见光辐射下的本征反应速率 k = 2.71×10mmol L min。
