Photoelectrochemical characterization of C/TiO2 and C/ZnO nanomaterials in aqueous electrolyte

Abstract

Carbon nanostructures, including single-walled carbon nanotubes, reduced graphene oxide, and carbon dots, are inserted in TiO2 and ZnO photoanodes with the aim of improving their activity. For the electrode assembly, TiO2 or ZnO nanoparticles, as well as carbon nanomaterials, are dispersed in a liquid and deposited on FTO by spray coating. Various mixed and layer-by-layer electrode configurations are considered. As-prepared electrodes are evaluated by photoelectrochemical (PEC) techniques, mostly cyclic voltammetry and transient photocurrent measurements. The insertion of the carbon component improves the photocurrent response depending on the measurement conditions, specifically the electrolyte pH and the presence of methanol as a hole scavenger. Therefore, hybrid carbon/semiconductor metal oxide nanomaterials can be applied in PEC processes for the production of hydrogen and the degradation of organic pollutants in water.