A dual-cathode photoelectrocatalysis-electroenzymatic catalysis system by coupling BiVO4 photoanode with hemin/Cu and carbon cloth cathodes for degradation of tetracycline

When photoelectrocatalysis (PEC) couples with electroenzymatic catalysis (EEC), effective utilization of electrons from PEC process for yield of H 2 O 2 plays an important role in the enzymatic catalysis. In the present work, we designed a novel dual-cathode PEC-EEC system for pollutant removal. In this system, BiVO 4 photoanode was prepared by electrodeposition for visible light-driven PEC process while carbon cloth was used as the first cathode for electrogeneration of H 2 O 2 and hemin/Cu prepared by electrophoretic deposition acted as the second cathode for enzymatic catalysis. The performances of the constructed dual-cathode PEC-EEC system were evaluated by decoloring Rhodamine B (RhB), which showed high decoloration percentage with acceptable stability and reusability. Further, the system was applied to degradation of tetracycline (TC), indicating that about 93.6% of TC was removed after 2-h treatment. A pathway for TC degradation in such a dual-cathode PEC-EEC system was proposed based on the intermediates determined by liquid chromatography coupled to mass spectrometry in tandem (LC-ESI-MS/MS).