Biological and optical properties of sol-gel derived ZnO using different percentages of silver contents.

The role of Ag dopant on ZnO thin films are studied. Ag doped ZnO thin films were deposited by sol-gel dip coating on glass substrates. The X-ray diffraction analysis shows hexagonal wurtzite with preferred orientation along the (101) plane. The crystallite size decreases from 33.40 nm to 28.37 nm with increase in silver doping percentage. Optical examination shows that the band gap decrease with an increase in the Ag doping in ZnO. The structural and optical results prove that Ag has substituted Zn in ZnO lattice. Silver doped ZnO is effective against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) bacteria. The roughness and the surface oxygen species accelerate the bacteria killing properties of Ag doped ZnO. They have pharmacological utility as a replacement of the antibiotics, bactericide and disinfectants. The TGA study showed that the thermal stability of the Ag doped ZnO takes place between 380-435 °C.