Positively charged 3-D interface mediated electrostatic adsorption of microorganisms for enhanced photocatalytic disinfection

[Display omitted] •A positively 3-D charged photocatalytic fabric was developed for water disinfection.•Positively charged interface effectively adsorbs negatively charged bacteria.•Bacteria were oxidized in situ by photoactive species on the fabric surface.•Synergy of adsorption and photooxidation enhances disinfection efficiency.•The fabric disinfect rainwater below WHO drinking water standard under sunlight. Photocatalysis offers a sustainable method for disinfecting natural drinking water. However, the photoactive species generated at the catalyst interface face challenges in migrating over long distances in water to interact with bacteria. In this study, we introduce an enhanced photocatalytic disinfection strategy involves the in-situ growth of fluorine-modified titanium dioxide heterostructure arrays on carbon fibers. This method results in a positively charged photocatalytic fabric that effectively attracts negatively charged microbes to its surface, significantly reducing the mass-transfer distance of active species. The heterophase junction between rutile nanorods and anatase nanoparticles enhances charge separation efficiency, while fluorine doping in anatase nanoparticles creates a positively charged 3-D interface conducive to electrostatic adsorption and in-situ oxidation of microorganisms. When tested in actual rainwater, this photocatalytic fabric successfully reduced the bacterial count from 4500 CFU/mL to below the WHO drinking water standard of 100 CFU/mL over three cycles in a single day under natural sunlight.