Study On The Preparation And Antibacterial Properites Of CuO/ZnO Composites

ZnO is a good antibacterial agent its antibacterial effect is mainly based on, the dissolution of metal ions and photocatalytic effect, but its application field is restricted by narrow spectralresponse range. Adding metal ions can improve the photocatalytic effect and rare earth doping can be used as excellent cocatalyst,based on the above recognitions, copper zinc composite oxide of doping rare earth element(Ce-Cu/ZnO) was prepared by using the ultrasonic assisted sol-gel auto-combustion method in this paper. The materials phase composition, microstructure, light absorption efficiency et al were studied,by testing means of TG-DTA, XRD, SEM, UV- Vis and PL. To explore the antibacterial mechanism of Ce-Cu/ZnO, the e.coli was used as object, and the influence factors on the properties of antibacterial effects such as the light source, heat treatment temperature, solvent, copper content and amount of cerium doped were studied. The experiental results showed that:When the copper content was 5 mol %, the Cu/ZnO sample prepared was observed by SEM morphology. The shape of the particles was spherical, the size was between 30 to 50 nm. The minim particle size was obtained for about 30 nm, while the ratio of alcohol and water in preparation solvents is 1:1, the e. coli antibacterial rate was 95.37%; the antibacterial rate against escherichia coli of Ce- Cu/ZnO composites rised up to 99.32% with good antibacterial durability,at the content of Cu of 5 mol%, Ce of 0.10 mol%, heat treatment temperature of 500 ℃,and the ratio of alcohol and water in preparation solvent of 1:1.The antibacterial rate of composite oxide increased by 4.1% after Co-doping. The antibacterial mechanism was that, helped to form a new energy level of ZnO,which could reduce the excitation energy of ZnO, meanwhile, the Ce3 +/Ce4 + could also be used as capture trap of electrons and holes to reduced the carrier recombination rate. On the surface of the material, redox reaction take place between large amount of electrons, holes and H2 O, O2. Active materials produced by redox reaction like ·OH, ·O2-, H2O2 have strong ability of oxidation,they can destroy bacteria cell wall and cell membrane, thus inhibiting the growth of bacteria breeding, enhanceing the antibacterial performance of Ce-Cu/ZnO.