Janus electrocatalytic flow-through membrane enables highly selective singlet oxygen production

The importance of singlet oxygen (O-1(2)) in the environmental and biomedical fields has motivated research for effective O-1(2) production. Electrocatalytic processes hold great potential for highly-automated and scalable O-1(2) synthesis, but they are energy- and chemical-intensive. Herein, we present a Janus electrocatalytic membrane realizing ultra-efficient O-1(2) production (6.9mmol per m(3) of permeate) and very low energy consumption (13.3Wh per m(3) of permeate) via a fast, flow-through electro-filtration process without the addition of chemical precursors. We confirm that a superoxide-mediated chain reaction, initiated by electrocatalytic oxygen reduction on the cathodic membrane side and subsequently terminated by H2O2 oxidation on the anodic membrane side, is crucial for O-1(2) generation. We further demonstrate that the high O-1(2) production efficiency is mainly attributable to the enhanced mass and charge transfer imparted by nano- and micro-confinement effects within the porous membrane structure. Our findings highlight a new electro-filtration strategy and an innovative reactive membrane design for synthesizing O-1(2) for a broad range of potential applications including environmental remediation. Electrocatalytic processes are promising for automated and scalable synthesis of singlet oxygen, but they are energy- and chemical-intensive. Here the authors present a Janus electrocatalytic membrane that selectively produces singlet oxygen with low energy consumption and free of chemical precursors.