Chitosan/Polyvinyl Alcohol/g-C3N4 Nanocomposite Film: An Efficient Visible Light-Responsive Photocatalyst and Antimicrobial Agent

Biopolymer-based nanocomposite film is an efficient material for addressing the increasing levels of pollutants in the environment and also for the production of antimicrobial packing material due to its good film-forming properties, biodegradability, and minimal environmental impact. In particular, chitosan/polyvinyl alcohol/g-C3N4 (CS/PVA/g-C3N4) nanocomposite films with different weight percentages of PVA were prepared using simple methodologies and characterized using XRD, TGA, FT-IR, DSC, FE-SEM, EDX, and elemental mapping analysis. The XRD and FT-IR results validated the nanocomposite film formation. The FE-SEM images showed the smooth surface of the composite films without any wrinkles: the smoothness of the film increased with increases in the PVA loading, and the surface morphologies of the films were largely unchanged. The EDX and elemental mapping analysis validated the presence and uniform dispersion of g-C3N4 within the nanocomposite film. The photocatalytic activity of the CS/PVA/g-C3N4 composite films was assessed by the degradation of rhodamine B dye (RhB) and acetophenone under direct sunlight irradiation. The CS/PVA/g-C3N4 nanocomposite films exhibited superior degradation efficiency toward the RhB dye and acetophenone compared to the bare polymeric film and the g-C3N4 material. The order of degradation for the RhB dye and acetophenone was CS/PVA (1.0) g-C3N4 (95.34%, 33.33%) &gt: CS/PVA (1.5) g-C3N4 (93.18%, 31.31%) &gt: CS/PVA (0.5) g-C3N4 (93.02%, 29.29%) &gt: CS/PVA (90.69%, 26.26%) &gt: g-C3N4 (87.56%, 24%), respectively. Furthermore, the antimicrobial activity of the nanocomposite films was tested against E. coli, Pseudomonas sps., Klesiella sps., and Enterococcus sps., and the CS/PVA (1.5)/g-C3N4 nanocomposite film offered better antimicrobial properties than the other composite films and bare materials. In conclusion, these biopolymer-based nanocomposites are highly efficient and provide a promising path for the development of various biodegradable polymeric nanocomposites for environmental remediation and antibacterial packing applications.