TiO2 nanocrystal particles and electrodes : the combined role of pH and metal substrate

In this work titania nanoparticles and layers, deposited onto metal supports (Ti and Au), have been prepared by combining a sol–gel precipitation with hydrothermal growth steps. This composite route implying also a final calcination at 300 C yields nanocrystalline anatase which shows the presence of electron trap sites localized within the band gap. The powders and layers are characterized for phase composition, crystallinity (XRD) and morphology (SEM). The role played by metal substrate and pH on the features of the electrodes were investigated by CV and impedance measurements.