Enhanced antibacterial activity of V-doped ZnO@SiO2 composites

• This study confirmed the effect of V 2 O 5 on the antibacterial activity of ZnO@SiO 2 composites by analyzing the crystal morphology, visible light absorption efficiency and charge carrier separation of the composites, • This study confirmed that the antibacterial activity of the V 2 O 5 -ZnO@SiO 2 composite material was attributed to three main mechanisms, i.e., Zn 2+ ions release from ZnO particles, ROS generation, and mechanical damage. • The results of this study provide an effective method to improve the antibacterial activity of ZnO by incorporating metals. 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. V 2 O 5 -ZnO@SiO 2 (V-ZS) composites, made of mesoporous SiO 2 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, N 2 physisorption, and XPS and the results were compared with those of undoped ZnO@SiO 2 composites. UV–vis and PL spectroscopies were used to investigate the enhancement effect of V 2 O 5 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 Zn 2+ from ZnO particles and promoted the generation of reactive oxygen species. The enhancement effect of V 2 O 5 depended on the percent of V 2 O 5 in V 2 O 5 /ZnO nanostructures. The results of antibacterial activity revealed that even at a small amount of V 2 O 5 (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.