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.