Synthesis, characterization and antibacterial activity of silver doped TiO2 photocatalyst

Abstract

Silver was doped into TiO2 semiconductor in order to improve the antibacterial activity of TiO2 photocatalyst under ultraviolet and visible light radiation due to its ability to modify the band gap energy of TiO2. Silver doped TiO2 photocatalysts were successfully synthesized using the sonochemical method at various silver concentration i.e 1,3,5,7, and 9%. Structural studies from XRD data showed that either undoped and silver-doped TiO2 crystallized in a single phase structure of anatase TiO2 with I41/amd space group. UV-Vis Diffuse Reflectance spectra resulted in the bandgap energy of undoped and silver-doped TiO2 were 3.4 eV, 3.0 eV, 3.3 eV, 3.1 eV, 3.25 eVand 2.8 eV respectively. Among those various dopant concentrations, 9% Ag-doped TiO2 showed the highest decrease in reflectance and band gap energy. Antibacterial activity of all synthesized materials toward E. coli antibacterial activity achieved the highest value for 9% of silver-doped TiO2 under ultraviolet and visible light irradiation. Zero viability occurred at 50mg/30mL of culture for 9% of Ag-doped TiO2 under visible irradiation. Inhibition zone and viability test confirmed that Ag content plays a significant role in increasing the antibacterial activity of silver-doped TiO2 photocatalyst.