Grafting Sulfonated Triptycene-Based Hypercrosslinked Polymers onto Bi₂WO₆ for Enhanced Adsorption and Photoelimination of Antibiotics

Antibiotics, as an emerging pollutant due to their extensive use and difficulty in biodegradation, can cause harm to health through bioaccumulation. To address this, various photocatalysts have been developed for rapid antibiotic removal. However, their low concentrations limit mass transfer efficiency, resulting in suboptimal performance. Adsorption is crucial for enhancing photocatalytic efficiency. In this study, a series of binary heterojunction catalysts (x% BWO@STHP) were synthesized, consisting of Bi₂WO₆ (BWO) grafted with sulfonated triptycene-based hypercrosslinked polymer (STHP). The high specific surface area of STHP, combined with π-π conjugation and ionic interactions with antibiotics, significantly enhances adsorption capacity. This facilitates effective contact between low-concentration pollutants in aqueous solutions and the active sites of the catalyst. The formation of a Z-scheme heterojunction between BWO and STHP facilitates photogenerated charge separation, and further significantly improves photocatalytic degradation performance. Specifically, the 20% BWO@STHP catalyst achieved rapid adsorption equilibrium for oxytetracycline (OTC), doxycycline (DOX), and tetracycline (TC) within 2 min and completely degraded them after 15 min of irradiation, compared to pristine BWO, the photocatalytic reaction rate constants are significantly increased, being 9.69 times higher for OTC and 13.45 times higher for DOX. The catalyst exhibits excellent reusability and holds promising potential for practical applications.