Evaluation of Chitosan/Bi2O2S Engineered Photocatalytic Film for Visible Light Stimulated Photocatalytic Degradation of Pharmaceutical Drugs

Abstract The growing interest in environmentally benign materials has driven the development of biopolymer-based systems for wastewater remediation. In this work, chitosan-based photocatalytic hydrogel film hybridized with Bi2O2S sub-micron particles was designed and fabricated for the efficient removal of pharmaceutical contaminants from wastewater. A comprehensive set of analytical techniques (including; FTIR, XRD, XPS, FE-SEM, DLS, UTM, and UV-vis) were employed to confirm the successful incorporation and interaction of Bi2O2S sub-micron particles within the chitosan network. The mechanical integrity of the fabricated film was evaluated using a universal tensile testing machine, demonstrating enhanced mechanical strength and robustness of the nanocomposite film. The prepared photocatalytic film exhibited highly efficient visible-light-driven photocatalytic degradation of the pharmaceutical drug doxorubicin (DOX), achieving a maximum degradation efficiency of approximately 95 % within 60 min. of irradiation. Furthermore, the photocatalytic film showed an excellent structural stability which can be attributed to the strong mechanical framework and stabilizing role of the chitosan hydrogel matrix. The chitosan film acted as a multifunctional platform by providing structural support, adsorption sites for pollutant molecules, and effective immobilization of Bi2O2S sub-micron particles, thereby enhancing photocatalytic performance. Owing to their green synthesis route, costeffectiveness, mechanical durability, and operational simplicity, the developed chitosan- Bi2O2S photocatalytic film demonstrates a strong potential for application in advanced and sustainable wastewater treatment technologies.