Photoelectrochemical properties of TiO2 nanofibers coated by copper oxide nanoparticles using sputtering and chemical bath deposition

TiO2 nanofibers (NFs), grown on Ti sheets by hydrothermal treatment, were coated with Cu2O nanoparticles (NPs) using sputtering or chemical bath deposition (CBD) in order to improve their photoelectrochemical (PEC) water splitting capabilities as photoanodes. Scanning electron microscopy (SEM) and X-ray photoelectron (XPS) spectroscopy confirmed the production of the desired Cu2O-TiO2/Ti hetero-nanostructures, while PEC measurements evidenced a net improvement of the produced photocurrent under standard xenon lamp illumination, compared to the pristine TiO2/Ti structure. Moreover, it appears that the sputtered composite photoanodes provide a higher photocurrent compared to the CBD made ones, meaning that their oxide/oxide interfaces are of better crystalline quality, supplying a larger number of electrons to the Pt cell cathode for H+ reduction to H2, through the external PEC cell circuit.