Enhanced surface wettability in Cu-doped TiO₂ thin films for solar driven catalytic applications

Currently, the development of the resources to pollution-free energy like the solar-driven hydrogen generation methods are the utmost priority to slow down the current rate of global warming. Metal oxide semiconductors say TiO₂, based photocatalyst materials, has proved themselves a better candidate for the solar driven water splitting. TiO₂ is a cost-effective wide bandgap semiconductor with a bandgap of 3.2 eV. Herein, we demonstrate that Cu doping in TiO₂ can significantly enhance surface wettability. The redshift in absorption spectra indicates a reduction in the bandgap. The enhanced hydrophilic nature of the photocatalyst material results in improving the surface area available for the photon induced reaction. The absorption spectra' redshift ensures that more solar spectrum should be utilized for hydrogen production via water splitting. Water contact angle measurement of TiO₂ surfaces reduces from 33.829° to 18.053° after copper doping. Our study concludes that transition metal doping (Cu) can help in tuning the bandgap and the surface wetting nature of the photocatalyst, which opens the pathways for developing more efficient photocatalytic materials for the cost-efficient hydrogen production.