A Novel and sustainable chitosan (CS)/ activated charcoal (AC) composites were prepared by cross linking with epichlorohydrine (ECH) to form a porous structure. Different titanium dioxide nanoparticles (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 e ciency toward rose bengal (RB) dye and the Culex Pipiens. The composites were characterized by FT-IR, XRD 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 signi cant 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/TiO2 NPs composite has an inhibitory effect and therefore considered as antibacterial agents. CS/AC/0.4%TiO 2 NPs showed maximum e cacy against larvicidal activity and pupicidal of mosquito vector which recorded 99.00 ± 1.14, 95.00 ± 1.43, 92.20 ± 2.64 for rst, 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.