Effect of manganese doping on the optical property and photocatalytic activity of nanocrystalline titania: Experimental and theoretical investigation

Abstract

• Mn doping distorts the TiO 2 lattice and generates oxygen vacancies. • Mn 3 d states are created in the band gap of TiO 2 . • Doping results in the blue shifting and broadening of the intense E g Raman peak. • Doping quenches emission intensity and increases lifetime of the charge carriers. • Mn doped TiO 2 enhances photocatalytic activity and red shift absorption edge. Nanocrystalline titania are doped with three different concentrations of manganese. The prepared nanoparticles have been characterized using different analytical techniques for analyzing their phase contents, nanocrystallite size distribution, band gap and photoluminescence. The changes in the property after doping are attributed to the introduction of Mn 3 d states that act as electron trapping states .To further justify the creation of these trap states that has some strong correlation in contributing to enhanced photocatalytic activity, theoretical calculation based on density functional theory using VASP Software has been considered .The structure of undoped and manganese doped TiO 2 has been adapted to the minimum energy level configuration and corresponding calculation of density of states have indicated the state responsible for enhancement of photocatalytic activity.