Optical characteristics and antimicrobial performance of Mg doped TiO2nanostructures synthesized by microwave assisted method

Abstract

Titanium dioxide (TiO2) and magnesium doped TiO2 with Mg concentration of 0.5, 1 and 2mol% were synthesized via a co-operating technique of direct microwave and traditional heating. The precursor was firstly heated by 800 w microwave oven and annealed at 300 °C for 3hr. The crystalline structure, morphology and optical properties were examined by X-ray diffraction (XRD), Scanning electron microscopy (SEM), UV-Visible spectroscopy (UV-Vis) and Photoluminescence technique (PL), respectively. As-synthesized products showed a phase of anatase TiO2 without Mg compound phase existence. The incorporation of Mg2+ in TiO2 crystal structures affected the shift of energy bandgap, the reduction of PL emission intensity and antimicrobial activity change. The energy bandgap with various dopant concentrations determines to be 3.13, 3.11, 3.07 and 2.97 eV. PL emission peaks are obtained around wavelength of 375nm and their emission intensity are greater when concentration of added Mg increase, indicating a higher electron- hole recombination rate. Pristine TiO2 exhibits a highest inhibition zone of 30mm against gram-positive Staphylococcus aureus (S.aureus).