On-site catalytic wastewater remediation by sustainably produced H₂O₂ via scalable single-atomic Fe-incorporated Janus membrane

Electrosynthesis of hydrogen peroxide (H2O2) from oxygen is a green and sustainable route toward on-site wastewater treatment. Nevertheless, the performance mismatch of the catalyst species and gas-diffusion components gives rise to low O2 utilization efficiency and limited H2O2 production rate in a practical cell. Herein, we propose a flexible and scalable Janus electrode comprising hydrophilic single-atomic Fe-incorporated catalytic layer and hydrophobic gas-attraction layer. The hydrophobic layer enables efficient oxygen diffusion, and the hollow-structured catalysts allow oxygen gas trapping with a high local oxygen concentration, resulting in a high Faradaic efficiency and fast H2O2 production rate. Accordingly, an 80 h electrocatalytic H2O2 synthesis could be gained at 80 mA cm−2. The Janus electrode delivers a H2O2 selectivity of 92% and a yield of 592 mmol g−1 h−1 in a flow cell. The thus-produced H2O2 allows for an in situ antibiotic removal, with the potential for on-site eco-restoration.