New insights into electrocatalytic singlet oxygen generation for effective and selective water decontamination

Abstract

Singlet oxygen (¹O₂), as an electrophilic oxidant, is essential for the selective water decontamination of pollutants from water. Herein, we showcase a high-performing electrocatalytic filtration system composed of carbon nanotubes functionalized with CoFe alloy nanoparticles (CoFeCNT) to selectively facilitate the electrochemical activation of O₂ to ¹O₂. Benefiting from the prominently featured bimetal active sites of CoFeCNT, nearly complete production of ¹O₂ is achieved by the electrocatalytic activation of O₂. Additionally, the proposed system exhibits a consistent pollutant removal efficiency >90 % in a flow-through reactor over 48 h of continuous operation without a noticeable decline in performance, highlighting the dependable stability of the system for practical applications. The flow-through configuration demonstrates a striking 8-fold enhancement in tetracycline oxidation compared to a conventional batch reactor. This work provides a molecular level understanding of the oxygen reduction reaction, showing promising potential for the selective removal of emerging organic contaminants from water.