Replacing carbon cloth by nickel mesh as substrate for air-diffusion cathodes: H2O2 production and carbenicillin degradation by photoelectro-Fenton

•Endurance of air-diffusion cathode for H2O2 synthesis: Nimesh superior to Ccloth as substrate.•Stable accumulation of H2O2 for 48 h: 60 mM at 100 mA with 3-cm2 Nimesh|C-PTFE ADE.•Viability of Nimesh|C-PTFE ADE for photoelectro-Fenton treatment of carbenicillin antibiotic.•Fast degradation (5 min at 100 mA) thanks to HClO co-generation, with > 80 % mineralization.•Monitoring of OH concentration, toxicity and byproducts (32 aromatic + 16 aliphatic)