Visible light active Bi₂S₃/ZIF-8 MOF composite for concurrent doxycycline degradation and antibacterial action

In order to address ecological and significant health concerns, this study investigates a unique water treatment solution using photocatalysis and antibacterial applications. A ZIF-8 based nanocomposite is synthesized via solvothermal formation by incorporating Bi₂S₃ into ZIF-8, followed by photodegradation of antibiotic doxycycline hydrochloride (DOX) and bactericidal approach against Gram-stained bacteria C. indologenes and S. aureus. The structure and properties of the composite are confirmed using all the characterization methods including P-XRD, FTIR, UV-DRS, SEM, BET, XPS, AC conductivity, dielectric constant and impedance study. The photodegradation efficiency is evaluated under varying parameters such as time, pH of the solution, catalyst dose and DOX concentration, with an impressive 81.43% degradation observed under visible light irradiation at pH 7 and a TOC of 64% in 90 min. This process follows Z-scheme mechanistic pathway and remains stable over four consecutive cycles. In addition, the composite demonstrates strong antibacterial activity against the bacteria. These findings suggest that the incorporation of Bi₂S₃ to ZIF-8 creates a synergistic effect, forming a robust heterogenous catalyst that is effective for both water purification and antibacterial applications.