Preparation and Antibacterial Activity of Silver Doping Nano Zinc Oxide

Zinc oxalate dihydrate as the precursor of anometer zinc oxide (nano-ZnO) was prepared by direct precipitation method. The zinc oxalate dihydrate was dispersed in a silver nitrate solution, and then the resulting solution was filtered and dried under 120°C. The silver doping nano-Zinc oxide (nano-SDZO) was obtained by decrepitating the zinc oxalate dihydrate cake under 500°C. The microstructure of nano-ZnO and nano-SDZO were characterized by TEM, and the chemical reaction in the heat burst process was described. The nano-ZnO particles were 50-60 nm in diameter, and the particle size of nano-SDZO in the range of 20-100 nm. Antibacterial activity of the nano-ZnO and nano-SDZO were compared. The results show that all of the ZnO samples inhibited the growth of S. aureus and E. coli, and nano-SDZO showed a relatively higher inhibition rate than other samples. Two possible mechanisms were proposed to explain the inhibition of bacteria.