Enhanced photodegradation of methyl orange dye under UV irradiation using MoO3 and Ag doped TiO2 photocatalysts

Titanium dioxide (TiO2) semiconductor-based photocatalysts have been widely utilized in the last few decades for water treatment because of their higher photocatalytic performance. Recently, most researchers have focused on the improvement of TiO2 semiconductors' photocatalytic performance through doping and co-doping with different metals and nonmetals during synthesis. The current study was conducted to synthesize TiO2 based photocatalysts, construct TiO2 photocatalysts based immobilized borosilicate glass (BG) reactors and applied the reactors for methyl orange (MO) dye treatment under UV irradiation. Based on XRD results, the dominant phase was anatase in all the photocatalysts. The largest amount anatase phase (82.43%) of Ag/MoO3/TiO2 photocatalyst in comparison to TiO2 (70.44%), MoO3/TiO2 (74.18%) and Ag/TiO2 (80.59%) photocatalysts were observed. The photocatalytic degradation of 10 ppm MO dye was found 59.5%, 63.1%, 70.6% and 75.8%, for TiO2, MoO3/TiO2, Ag/TiO2, and Ag/MoO3/TiO2 photocatalysts, respectively, for a particular dose of photocatalyst (0.12 g) immobilized on BG at pH (7.0) after 5.5 h of UV-irradiation. The efficiency of the photocatalyst (Ag/MoO3/TiO2) was decreased with the increase of pH and initial dye concentrations. However, increasing photocatalyst and hydrogen peroxide doses in the BG reactor resulted in a better performance as expected. The first-order reaction rate constants were 0.003, 0.002, 0.003, and 0.004 min-1 for TiO2, MoO3/TiO2, Ag/TiO2, and Ag/MoO3/TiO2, respectively, for 0.12 g of photocatalyst dose. The outcomes suggest future possibilities of applying Ag/MoO3/TiO2 nanocomposite in the treatment of textile wastewater under UV irradiation. (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).