Solar-Driven Dual-Photoelectrode Photo Fuel Cell for Electricity Generation and Pollutant Degradation via In Situ Produced H₂O₂

Utilization of solar energy to generate green electricity and degrade organic pollutants shows high promise for developing renewable energy and a sustainable eco-environment. Herein, we fabricate a dual-photoelectrode photo fuel cell (DP-PFC) by assembling photoelectrodes of ZnO/TiO2 and polyterthiophene (pTTh)/CuOx in one chamber without using a membrane separator. The DP-PFC simultaneously delivers a maximum power of 0.4 mW cm–2 and shows a degradation rate of 97.3% for the decomposing dye in 2 h under simulated sunlight illumination. Furthermore, we found that the pTTh/CuOx photocathode contributes more than the ZnO/TiO2 photoanode for dye degradation, and the decomposition kinetic constant of pTTh/CuOx is 1.6 times that of ZnO/TiO2. The reason is mainly attributed to the efficient production of H2O2 on the pTTh/CuOx. Meanwhile, the hydroxyl radical (·OH), originating from the deep reduction of the in situ produced H2O2, turned out to be the primary active species responsible for the dye degradation. This work offers an effective and environmentally benign device for two purposes of generating green electricity and decomposing pollutants simultaneously.