Visible Light Photocatalytic Activity of Manganese Doped TiO2 Nanoparticles

In this paper we report the successful synthesis of manganese (Mn²⁺) doped TiO₂ nanoparticles by sol-gel method. Optical properties of the nanoparticles were characterised by UV-Vis spectrometer in the range 200-900nm and a photoluminescence spectrometer to study the emission spectra of both doped and undoped particles. The UV-Vis spectra of the doped samples shows signature of peaks in the visible region, attributed to the charge transfer transitions between the metal ion d electrons and the conduction or valence band of TiO₂. XRD study shows that upon doping with Mn²⁺ the crystallite size decreases inferring that the dopants effectively inhibits TiO₂ grain growth by staying at grain boundaries . Photocatalytic activities of the TiO₂ samples modified by Mn²⁺ ions have been found to be higher than that of pure TiO₂.