Photocatalyst immobilization on biopolymers presents a promising avenue for air purification, yet achieving efficient immobilization and purification methods remains a challenge. In this study, we develop a novel, straightforward sequential coating technique to fabricate cellulose film embedded with uniformly dispersed TiO2 submicrospheres and Ag-AgCl nanoparticles (NPs), tailored for effective indoor air purification under sunlight exposure. The obtained Ag-AgCl/TiO2/cellulose film exhibit remarkable photocatalytic prowess in degrading various volatile organic compounds (VOCs, including ethanol, 1-propanol, 1-butanol, propylamine, and propanethiol) under simulated sunlight, owing to the enhanced separation of charge carriers facilitated by the presence of plasmonic Ag-AgCl NPs. Notably, the nature of the functional groups and the carbon atom count within the VOCs molecular structures exert significant influence on the overall photocatalytic performance. Furthermore, our investigation into the reusability of this biocomposite film confirms its durability, particularly in mineralizing alcoholic compounds during VOC oxidization, and the deactivation primarily occurs with VOCs containing heteroatoms that can be residual on biocomposite surface. This study represents a significant step towards practical applications of biocomposite films with efficient photocatalytic activities for real-world air purification and environmental remediation.