Boosting the visible-light-driven photocatalytic antibacterial performance of MoS nanosheets by poly(3-(4-methyl-3′-thiophenoxy))propyltrimethylammonium chloride (PThM) modification

Molybdenum disulfide (MoS 2 ) has been reported to possess photocatalytic bactericidal ability, but its efficiency is not high. In this paper, a water-soluble cationic conjugated polymer, poly(3-(4-methyl-3′-thiophenoxy))propyltrimethylammonium chloride (PThM), was designed to modify MoS 2 and boost its antibacterial abilities. Another hydrophobic conjugated polymer, polythiophene (PTh), was synthesized and composited with MoS 2 , and this was compared with PThM/MoS 2 from the perspective of composite effectiveness. Studies involving the photo-disinfection of Escherichia coli ( E. coli ) under visible-light irradiation (30 W) showed that the antibacterial efficiencies were in the following order: PThM/MoS 2 > PTh/MoS 2 > MoS 2 . The enhanced bactericidal activities of PThM/MoS 2 and PTh/MoS 2 were attributed to the conjugated polymers restraining the recombination of photogenerated carriers in MoS 2 , thereby increasing the generation of reactive oxygen species (ROS). PThM/MoS 2 presented the best antibacterial efficiency because its cationic side-chains improved the solubility of the material and promoted contact between bacteria and the material. This work may provide some insights into the design of practical nano-antibacterial materials. A schematic diagram of the synthesis of PTh/MoS 2 and PThM/MoS 2 and their use in the inactivation of E. coli .