In situ visible/UV-light effective degradation of pure and mixed bentazon, diclofenac, and methyl-orange pollutants on BiOBr nanoplates UiO-66 nanoparticle-decorated, sonochemically

In this study, BiOBr nanoplates decorated with pre-synthesized UiO-66 nanoparticles (0, 5, 7.5, 10, and 15 wt.%) were prepared through in situ sonicated spontaneous precipitation and examined in the elimination of pure and mixed bentazon, diclofenac and methyl-orange under UV and visible light. The samples were characterized by XRD, FESEM/EDX, N₂ adsorption-desorption, FTIR, UV-Vis and PL techniques. The variation of UiO-66 content reduced BiOBr nanoplate overlapping up to 7.5 wt.%, improving optical and surface characteristics. However, the further decoration alleviates the synergetic impact of UiO-66 because of the surface coverage of BiOBr nanoplates and weak intra-particles interaction. In accordance with characterization results, an increase-decrease trend was observed for adsorption capacity and photocatalytic performance of bentazon degradation. Accordingly, 7.5 wt.% seems to be the optimum content of UiO-66 nanoparticles for the structural decoration of BiOBr nanoplates which can effectively eliminate bentazon, diclofenac and methyl-orange, and various combinations of these three organic pollutants. Under UV light irradiation, the optimal composite photocatalyst (BU-7.5) eliminates 80% of bentazon, 85% of diclofenac, and 100% of methyl-orange, respectively. The same pollutants are eliminated under visible light irradiation (LED lamp) at 68%, 71.5%, and 99.8%, respectively. Moreover, the impact of photocatalysis conditions including photocomposite dosage, concentration and composition of contaminants, solution pH, and illumination time on the photocatalytic performance was assessed using one factor at a time (OFAT) approach. In optimum photocatalysis conditions, the reusability results and post-characterization confirm the sustained performance and structural stability of the UiO-66-decorated BiOBr photocomposite. Finally, a reaction mechanism was also proposed.