Enhanced antibacterial activity of V-doped ZnO@SiO2 composites

Abstract

Zinc oxide (ZnO) is an antibacterial agent with great potential in biological applications. However, the antibacterial activity of ZnO is relatively weak. In this study, a method of doping ZnO crystals with metals was employed to improve its antibacterial activity. V2O5-ZnO@SiO2 (V-ZS) composites, made of mesoporous SiO2 as a carrier, ZnO as an antibacterial agent, and V as a doping element, were fabricated by hydrothermal method at atmospheric pressure. The morphology, crystal structure, and chemical composition of V-ZS composites were analyzed by SEM, TEM, XRD, N2 physisorption, and XPS and the results were compared with those of undoped ZnO@SiO2 composites. UV–vis and PL spectroscopies were used to investigate the enhancement effect of V2O5 on the visible light absorption and separation of photogenerated carriers. The doping of ZnO with V was found to be favorable for the release of Zn2+ from ZnO particles and promoted the generation of reactive oxygen species. The enhancement effect of V2O5 depended on the percent of V2O5 in V2O5/ZnO nanostructures. The results of antibacterial activity revealed that even at a small amount of V2O5 (8%), action of the resulting 8%V-ZS composite increased against bacteria. It was also shown that V-ZS composites can mechanically damage the bacteria. The results obtained herein sustain the use of the developed composites in antibacterial products.