Solar light induced antibacterial performance of TiO2 crystallized glass ceramics

This work investigates the antibacterial potential of TiO2-based glass-ceramic. A glass of TiO2 microcrystals embedded in glass matrix of BaO-TiO2-B(2)O(3)was obtained by melt quench method followed by controlled heat treatment at the 650 degrees C for 3hours. Crystallization of anatase phase of TiO2 was confirmed by X-ray diffraction. UV-visible absorbance and photoluminescence were also recorded. Interestingly band gap of TiO2 glass-ceramic (crystallized glass) was found to be 2.9 eV. Crystallized glass showed excellent antibacterial property against Escherichia coli in both forms (powder and plate). More than 90% of disinfection was achieved by photocatalytic TiO2 glass-ceramic surface within one hour of sunlight exposure, which was significantly higher than as-quenched glass surface and TiO2 glass-ceramic surface under dark. Intracellular reactive oxygen species (ROS) intensity of bacterial cells in the presence of crystallized glass was almost three times higher than the control and as-quenched glass under light. Higher production of ROS is major factor for bacterial degradation on crystallized glass surface.