Surface sulfate modified TiO2 visible light active photocatalyst for complex wastewater purification: Preparation, characterization and photocatalytic activity

One of the major concerns of today's society is the rapid deterioration of our environment. Wastewater purification via catalysts could be a solution for a part of this situation. Related to this topic. Related to this topic here we report the facile preparation of surface-modified TiO2 photocatalyst performed by simply grinding and calcination process, using elemental sulfur originated from the desulfurization of petroleum.Visible light active (Eg = 2.91 eV) sulfur modified TiO2 were prepared with low surface charge (-62.2 & PLUSMN; 0.7 mV). The improved photocatalytic activity of sulfated samples was proved via benzoic acid photodegradation tests under visible light and compared to the reference P25. According to the re-sults, the sulfated TiO2 degraded 41% of the initial benzoic acid, while TiO2 degraded only 27%. Next mechanically stable photoreactive composite layers were prepared using the ST-benzene catalyst and it was presented that the thin film can successfully degrade the model water. In the complex sample, the ST-benzene containing photocatalyst layer's efficiency was 25.3% for phenol, 20.3% for niacin, 30.0% for paracetamol, 10.6% for caffeine and 28.8% for imidacloprid respectively. In addition, it is also presented that the sulfated photocatalyst is able to generate more hydroxyl radicals (which depends on the reaction rate constant of 7-hydroxycoumarin formation, k (ST-benzene) = 6.682 x10 (-5) mu molxL(-1) x s (-1)) than the initial P25 TiO2, which makes it a promising photocatalyst for water purification.(c) 2022 Elsevier B.V. All rights reserved.