Abstract:
Pharmaceutical contaminants in water represent a growing environmental concern due to their persistence and potential ecotoxicity. In this study, a hybrid Bi2WO6@WS2-PVDF-HFP (Poly(vinylidene fluoride-co-hexafluoropropylene) film was developed and evaluated as a sonophotocatalytic platform for the efficient degradation of trimethoprim (TMP) in both model and real water matrices. Comprehensive structural, optical, and electrochemical characterization confirmed the successful formation of a Bi2WO6@WS2 heterojunction, with strong interfacial coupling, S-scheme band alignment, and enhanced charge separation. UV–Vis and Tauc analyses revealed broadened visible-light absorption, while photocurrent and EIS (Electrochemical Impedance Spectroscopy) measurements demonstrated improved charge carrier transport and reduced recombination. Functional testing showed that the hybrid film achieved complete TMP degradation under combined light irradiation and ultrasound, outperforming individual Bi2WO6 and WS2 components. Kinetic studies indicated predominantly pseudo-first-order behavior, with the highest rates observed under sonophotocatalytic conditions (k1 = 2.587 × 10−2 min−1 for Bi2WO6@WS2 powder and k1 = 3.016 × 10−2 min−1 for Bi2WO6@WS2-PVDF-HFP), and synergy factor (SF) analysis confirmed strong synergistic interaction for the powder (SF = 2.36) and predominantly additive behavior for the film (SF = 0.97). Adsorption studies indicate favorable monolayer adsorption on catalyst active sites together with heterogeneous adsorption on the polymer matrix. Importantly, performance in surface and groundwater was comparable to that in deionized water, demonstrating robustness across complex matrices. The film maintained 100% TMP degradation efficiency across three consecutive cycles, demonstrating its reusability and stability. Liquid chromatography-mass spectrometry (LC-MS) analyses revealed that hybrid sonophotocatalysis not only accelerates degradation but also promotes deeper fragmentation of TMP into smaller, less toxic transformation products, thereby minimizing the formation of harmful by-products. These results underscore the potential of Bi2WO6@WS2-PVDF-HFP films as a scalable, efficient, and environmentally friendly solution for remediating emerging contaminants in real water systems..
Title: Interfacially coupled Bi2WO6@WS2-PVDF based film for sonophotocatalytic trimethoprim removal: From material engineering to surface- and groundwater applications
Authors: D. Czekanowska, H. Salazar, J. Sáiz, A. Šarakovskis, A. Antuzevics, S. Lanceros-Mendez, A. Kholkin, P. Głuchowski
Reference: Chemical Engineering Journal, 537, 176180, 2026
