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 E. coli 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.