Carbon-based electrocatalytic dual-membrane system bolsters singlet oxygen production for ultrafast water decontamination

Reactive electrochemical membranes (REMs) are promising technologies in treating pharmaceuticals and personal care products (PPCPs) in water. Herein, a novel carbon-based electrocatalytic dual-membrane system was designed to exploit the whole redox process of electrodes, in which the membrane cathode and anode were formed by carbon fibers doped with Fe and metal organic frameworks derived SnO2, respectively. Propranolol (PRO) was used as a representative of PPCPs. The system bolstered singlet oxygen (1O2) production by the synergy of two REM electrodes, further improving the removal rate constant of PRO compared with single-electrode-dominant modes. 97.5 ± 1.7% of PRO removal was achieved in a single-pass electro-filtration at a residence time of ∼2.9 s. The generation of 1O2 and its reaction with pollutants were systematically and thoroughly explored via experiments coupled with theoretical calculation. The toxicity of the decomposition products was predicted to be reduced compared with PRO. These findings suggested that the carbon-based electrocatalytic dual-membrane system could effectively promote 1O2 production for ultrafast catalytic oxidation of PRO, providing a cost-effective solution for the development of an efficient and stable technology for PPCPs removal.