Solar light-driven simultaneous pharmaceutical pollutant degradation and green hydrogen production using a mesoporous nanoscale WO3/BiVO4 heterostructure photoanode

Photoelectrocatalysis is one of the most favourable techniques that could be used in this remit as it has the potential to utilise natural sunlight to generate oxidants in situ to mediate effective pollutant degradation. This work, therefore, utilises a mesoporous nanoscale WO3/BiVO4 heterostructure photoanode to effectively degrade ibuprofen in wastewater combined with simultaneous green hydrogen generation at the cathode under simulated sunlight. A near complete degradation (>96%) of ibuprofen (starting concentration of 100 mg/L), with no hazardous intermediates (determined via mass spectrometry analysis), along with simultaneous H2 evolution of 114 µmol/cm2 after 145 min was demonstrated in this work. In addition, intermediate product analysis, the role of the type of in situ oxidants on degradation, the mechanistic pathway of degradation, and the material characteristics of mesoporous photoanode were also investigated. First experimental evidence of in situ generated H2O2 contributing to the degradation of ibuprofen is presented.