Rapid and complete inactivation of pathogenic microorganisms by solar-assisted in-situ H2O2 generation using a polypyrrole-supported copper sulfide system

Abstract

In this study, we report a photo-assisted H2O2 self-supply and in-situ activation system based on the polypyrrole-supported copper sulfide (solar/Cu2−xS@PPy) for water disinfection. 6.57-log, 4.22-log, and 5.23-log inactivation of Escherichia coli K-12 (even at a viable but nonculturable state), Bacillus subtilis spores, and bacteriophage MS2 are achieved within 60 min by using the solar/Cu2−xS@PPy system in batch and flow-through reactors. Catalyst characterization and theoretical calculation results suggest that the photo-generated H2O2 is in-situ activated by the Cu−N bridges in Cu2−xS@PPy·H2O2 is oxidized to •O2- and ultimately 1O2 on Cu sites, and electrons are subsequently pumped to electron-rich N sites (H2O2→Cu→N) to maintain the balance of electron donation-acquisition. The electrons can be directly extracted from cell membranes to Cu2−xS@PPy, making cells vulnerable to reactive oxygen species and heat. This work provides a novel and affordable solution for the rapid disinfection of drinking water in rural and underdeveloped areas.