Comparative Study of EPR and Optical Properties of CdS, TiO2 and CdS-TiO2 Nanocomposite

An economical chemical route is used to synthesize a titanium oxide-based nanocomposite (NC) which has properties that may help to develop photocatalysts with improved efficiency in the visible region of solar light. Investigation of opto-electronic properties has been carried out for a CdS, TiO2 and CdS-TiO2 NC at room temperature. Structural properties of the CdS and TiO2 nanoparticles and the CdS-TiO2 NC were investigated using x-ray diffraction and transmission electron microscopy techniques. How incorporation of CdS nanoparticles affects the structural properties of pure TiO2 was also studied. Change in optical behavior was compared using UV-visible and photoluminescence spectra, and the presence of residual functional groups were indicated by Fourier-transform infrared analysis of the samples. The measurement of band levels was carried out by cyclic voltammetry (CV) and the band gap estimated from UV-visible was compared to that obtained by CV. The electron paramagnetic resonance technique was used for the investigation of the electronic properties of the samples.