Simultaneous generation of residue-free reactive oxygen species and bacteria capture for efficient electrochemical water disinfection.

Abstract

Residue-free and highly efficient techniques for drinking water disinfection are urgently needed. Herein, we report an electrochemical water disinfection system equipped with atomically precise Ag₂₈ nanoclusters (NCs) as electrode materials. The deployment of these Ag₂₈ NCs not only provides sufficient electrosorption sites for intelligent microbe enrichment but also ensures high-efficiency dual-mode microbial killing through the in situ electrocatalytic production of residue-free reactive oxygen species (ROS) and the inherent antimicrobial activity of Ag₂₈ NCs. Moreover, the design of the system enables a cyclical "alive microbe capture-killing-dead microbe desorption" process for continuous water disinfection. On this basis, this water disinfection system is efficient against broad-spectrum microbes (with >99.99% antimicrobial activity), durable (with a performance reduction of only 0.75% over 40 cycles and 99.90% antimicrobial efficiency for over 5 h of continuous operation), versatile (i.e., other NCs can be used), scalable (with water productivity of 213.33 L h^-1 m^-²), energy efficient (with a low energy consumption of 4.91 Wh m^-³; 1.04 Wh m^-³ without the pumping cost) and applicable for various real water samples. This study may open new avenues for global water disinfection techniques.