Removal of Cetirizine Dihydrochloride from Different Matrices Waters Using Bi2O3/TiO2 Photocatalyst Under Simulated Solar Irradiation: Kinetics, Mechanism, and Effect of Environmental Media

Abstract

In this study, the photodegradation of cetirizine dihydrochloride (CET) by Bi<inf>2</inf>O<inf>3</inf>/TiO<inf>2</inf> heterojunctions under simulated solar light irradiation (300-800nm) was examined in detail for the first time. A hydrothermal synthesis of the photocatalyst was carried out, and several analytical techniques were used to characterize the product. The resulting Bi<inf>2</inf>O<inf>3</inf>/TiO<inf>2</inf> photocatalyst effectively removed CET from an aqueous solution. The Bi<inf>2</inf>O<inf>3</inf>/TiO<inf>2</inf> (5.0%/95.0%) ratio exhibited the highest photocatalytic performance for CET degradation, degrading 75.85% of CET after 60 min of irradiation, with a high pseudo-first-order rate constant (k<inf>app</inf> = 0.022 min−1; t<inf>1/2</inf> = 31.50 min; natural pH). Moreover, TOC decreased by 40.45% after 420 min of irradiation. The Bi<inf>2</inf>O<inf>3</inf>/TiO<inf>2</inf> photocatalyst has also been proven effective in degrading CET in different real aqueous matrices (Seawater (99.89%) > spring water (68.44%) > tap water (52.62%)), and the degradation under natural solar irradiation is more effective and faster than under artificial irradiation. Additionally, the Bi<inf>2</inf>O<inf>3</inf>/TiO<inf>2</inf> photocatalyst demonstrated excellent photo-stability in a five-cycle photocatalytic experiment. The influence of various parameters showed that the removal of CET was heightened with a dose of 1 g/L of the Bi<inf>2</inf>O<inf>3</inf>/TiO<inf>2</inf> and enhanced under acidic conditions (pH = 2.3). Moreover, the involvement of different reactive species was investigated by introducing diverse scavengers, revealing that hydroxyl radicals and photo-holes were the main reactive species involved in the CET photodegradation process over the Bi<inf>2</inf>O<inf>3</inf>/TiO<inf>2</inf> photocatalyst. The primary photodegradation byproducts were identified using HPLC–MS analysis, and a possible mechanism was proposed. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.