Enhancement of photocatalytic and biological activities of chitosan/activated carbon incorporated with TiO 2 nanoparticles

Novel and sustainable chitosan (CS)/activated charcoal (AC) composites were prepared by cross-linking with epichlorohydrin (ECH) to form a porous structure. Different titanium dioxide nanoparticle (TiO 2 NPs) concentrations (0, 0.2, 0.4, and 0.8% w/w) were added to enhance the photocatalytic, antibacterial, larvicidal, and pupicidal activities’ efficiency toward Rose Bengal (RB) dye and the Culex pipiens . The composites were characterized by FT-IR, XRD, XPS, BET and SEM. The SEM images revealed the porous structure of CS/AC and TiO 2 nanoparticles were uniformly distributed in the CS/AC matrix. The degradation of RB dye was used to test the photocatalytic behavior of the composites. Supporting TiO 2 on a CS/AC matrix resulted in a significant increase in photocatalytic performance. The antibacterial activities supported by CS/AC/TiO 2 NPs were evaluated by bacterial growth inhibition against B. subtilis , S. aureus , E. coli , and P. aeruginosa . The results showed that CS/AC/TiO 2 NPs composite has an inhibitory effect and therefore considered antibacterial agents. CS/AC/0.4%TiO 2 NPs showed maximum efficacy against larvicidal activity and pupicidal of mosquito vector which recorded 99.00 ± 1.14, 95.00 ± 1.43, and 92.20 ± 2.64 for the first, second, and third larval instars and 66.00 ± 2.39 for pupal mortality, while the repellent activity reported high protection at 82.95 ± 2.99 with 3.24 mg/cm 2 dose compared to control DEET.