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This review examines various modification techniques, including metal doping, non-metal doping, multi doping, mixed doping, and the construction of heterojunction photocatalysts, for enhancing the performance of pure TiO 2 and ZnO in the photodegradation of antibiotics. The study finds that mixed and multi doping approaches are more effective in improving photodegradation performance compared to single doping. Furthermore, the selection of suitable semiconductors for constructing heterojunction photocatalysts is crucial for achieving an efficient charge carrier separation. The environmental impacts, recent research, and real application of photocatalysis process have been discussed. The review also investigates the impact of operating parameters on the degradation pathways and the generation of by-products for different antibiotics. Additionally, the toxicity of the by-products resulting from the photodegradation of antibiotics using modified ZnO and TiO 2 photocatalysts is explored, revealing that these by-products may exhibit higher toxicity than the original antibiotics. Consequently, to enable the widespread implementation of photodegradation systems, researchers should focus on optimizing degradation systems to control the conversion pathways of by-products, developing innovative photoreactors, and evaluating toxicity in real wastewater matrices., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Due to the anthropogenic pollution, especially the environmental crisis caused by air pollutants, the development of air pollutant degradation photocatalyst has become one of the major directions to the crisis relief. Among them, titania (titanium dioxide, TiO 2 ) family materials were extensively studied in the past two decades due to their strong activity in the photocatalytic reactions. However, TiO 2 had a drawback of large bandgap which limited its applications, several modification techniques were hence developed to enhance its catalytic activity and light sensitivity. In recent years, other metal oxide based materials have been developed as replacements for TiO 2 photocatalysts. In this review, background information and developments from pure TiO 2 to chemically modified TiO 2 -based materials as photocatalysts were discussed in detail, which covered their basic properties and their role in the air pollutant removal. It also proposes to solve the shortcomings of TiO 2 by developing other metal oxide-based materials and predict the future development of TiO 2 materials in future environmental applications., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Ag/TiO 2 catalysts were prepared via in-situ synthesis and impregnation methods. The effect of redox state of Ag species on catalytic activity of Ag/TiO 2 catalysts was studied. The Ag-i-300 catalyst with partially oxidized state of Ag species shows superior catalytic activity, keeping HCHO removal efficiency at an extraordinary level of 100% during the 200 min's reaction. The Ag/TiO 2 catalysts were characterized by XPS, UV-Vis, BET, XRD, TEM, and in-situ DRIFTS technologies. XPS and TEM results exhibit that the partially oxidized state of Ag δ+ (0 < δ < 1) and high dispersion of Ag species are beneficial for the oxidation of HCHO over Ag/TiO 2 catalysts. According to the above results, a reaction pathway for HCHO oxidation over Ag-i-300 catalyst was also proposed., (Copyright © 2018 Elsevier Ltd. All rights reserved.)