Synergistic Engineering of a Cationic Polymer–Ag Catalyst Matrix with Enhanced Electrochemical Generation of Reactive Oxygen Species for Energy-Efficient Pathogen Inactivation at Lab Scale and in Municipal Effluent

Commercial wastewater disinfection technologies are inadequate for achieving rapid, durable, and energy-efficient pathogen removal, particularly against high loads of E. coli in sewage treatment plant (STP) effluents. In this context, we have developed an engineered material comprising 1-(carboxymethyl)pyridin-1-ium (IL-5)-functionalized polyethylenimine (PD5) and Ag nanoparticles (PD5-Ag) via σ/π–d band interactions. After analyzing its biosafety by cytotoxicity analysis, it was integrated into a chitosan/poly(vinyl alcohol) (CHPV) matrix at varying concentrations. The combined effect of electron modulation of Ag by PD5 via σ/π–d band interactions and integration with the CHPV matrix enhances its electrocatalytic activity, rapid reactive oxygen species (ROS) generation, and minimum catalyst loss. The optimized PD5-Ag/CHPV-4 matrix demonstrated high electrochemically active surface area, low Tafel slope, and minimal Ag leaching. Moreover, it achieved complete E. coli inactivation within 8 min through a “latch–kill–detach” mechanism and retained 94.7% efficacy after 200 cycles. It effectively disinfected the STP effluent, thereby highlighting its practical applicability as an energy-efficient electro-disinfection platform for safe municipal water reuse.