Electrocatalytic Generation of Singlet Oxygen via ROS-Mediated Redox Chain Reaction for Efficient Disinfection.

Abstract

The risk of harmful microorganisms to ecosystems and human health has stimulated exploration of singlet oxygen (¹O₂)-based disinfection. It can be potentially generated via an electrocatalytic process, but is limited by the low production yield and unclear intermediate-mediated mechanism. Herein, we designed a two-site catalyst (Fe/Mo-N/C) for the selective ¹O₂ generation. The Mo sites enhance the generation of ¹O₂ precursors (H₂O₂), accompanied by the generation of intermediate ^•HO₂/^•O₂^-. The Fe site facilitates activation of H₂O₂ into ^•OH, which accelerates the ^•HO₂/^•O₂^- into ¹O₂. A possible mechanism for promoting ¹O₂ production through the ROS-mediated chain reaction is reported. The as-developed electrochemical disinfection system can kill 1 × 10⁷ CFU mL^-1 of <i>E. coli</i> within 8 min, leading to cell membrane damage and DNA degradation. It can be effectively applied for the disinfection of medical wastewater. This work provides a general strategy for promoting the production of ¹O₂ through electrocatalysis and for efficient electrochemical disinfection.