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　com-ponents　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.