Preparation and characterisation of visible light responsive iodine doped TiO2 electrodes

Characteristics are presented of new iodine doped TiO2 (I-TiO2) prepared via the hydrothermal method, where titania (IV) complexes with a ligand containing an iodine atom have been used as a precursor. The structure of samples has been examined by XPS, XRD, UV–vis and FT-IR-ATR techniques. These studies confirm that the obtained powder exhibits a decrease in the bandgap energy value (Eg = 2.8 eV). The report presents electrochemical studies of I-TiO2 films on a Pt electrode, which allow determination of the flatband potential Efb = −0.437 V vs. SCE (in 0.5 M Na2SO4). Cyclic voltammetry measurements show anodic and cathodic activities under Vis and UV–vis radiation. The photocurrent enhancement due to visible light radiation reached 30% of the whole photoacitivity exhibited under UV–vis illumination.