Rolling-made gas diffusion electrode with carbon nanotube for electro-Fenton degradation of acetylsalicylic acid.

H2O2 production plays an important role in electro-Fenton process for pharmaceutical and personal care products (PPCPs) degradation. In this work, carbon nanotube (CNT) was attempted to make a gas diffusion electrode (GDE) by rolling method to achieve a high H2O2 production and current efficiency, and it was further used as electro-Fenton cathode for the degradation of acetylsalicylic acid (ASA) as one kind of PPCPs. The optimal amount of catalyst layer was 0.15 g CNT and 93.75 μL PTFE, obtaining the production of H2O2 of 805 mg L-1 in 0.05 mM Na2SO4 solution at 100 mA after 180 min. The degradation of ASA by electro-Fenton on such a CNT-GDE cathode was studied, and some important parameters such as current, pH as well as the dosage of Fe2+ were optimized. The degradation ratio of ASA could achieve almost 100% after 10 min and the TOC removal ratio was 62% at 1 h under the condition of 100 mA and pH 3, showing a great potential for the treatment of PPCPs.