Research On Preparation And Biological Effects Of Nano-Cu²⁺/TiO₂ Sol

In this paper, we synthesized nano-TiO₂ sol, and studied its preparation, modification, activity and application. Nano-TiO₂ with metal ion doping modification was obtained through adding metal salts during the process of preparation. Nano-TiO₂ thin film and Mⁿ⁺/TiO₂ thin film were prepared by spraying sol on the surface of ceramics, glass and plastic. The photocatalytic activity of nano-TiO₂ thin films and Mⁿ⁺/TiO₂ thin films were studied and compared through photocatalytic degradation of methylene blue solution and the inhibition of E. coli under UV irradiation. Nano-Cu²⁺/TiO₂ sol, which had the highest photocatalytic activity, was selected to study its effects on Avian Influenza Virus (H9 H2) disinfection, Cucumber Botrytis cinerea spores'germination and photosynthesis of Cucumber leaves. The main research results include:1: Nano-TiO₂ sol and Mⁿ⁺/TiO₂ sol, which are neutral, semi-transparent and have strong capacities of stability, adhesion and thin film-forming, were synthesized by referenced Ichinose's law, using TiCl4 as raw materials, NH 3 ?H2O as a precipitating agent, H2O2 as a complexing agent. The morphology, dispersion, crystal form and particle size were characterized by sub-micron particle size and potential analyzer, transmission electron microscopy, and scanning electron microscopy. The results showed that the synthesized nano-TiO₂ and Cu²⁺/TiO₂ particles were tapered shape and anatase crystal phase, uniformly distributed in the sol, with an average diameter of 58.4nm and 30.7nm.2:Nano-TiO₂ thin films and M n+/TiO₂ thin films were prepared through spraying on the surfaces of clean ceramics, glasses and plastics. Their photocatalytic decomposition ability towards methyl blue was studied. The results showed that the nano-TiO₂ sol and Mⁿ⁺/TiO₂ sol had a good photocatalytic activity, which could rapidly decompose methyl blue dye. Nano-TiO₂'s photocatalytic activity was improved through metal ion doping. In the experiment, doping of Cu²⁺, Fe 3+ and Mn2+ at 0.1% 1.0% (M and the amount of substance ratio of Ti) improved the nano-TiO₂'s capacity of photocatalytic decomposition of methyl blue. The capacity of its decomposition strength is Cu²⁺/TiO₂>Mn2+/ TiO₂>Fe 3+/TiO₂ >TiO₂, and 0.1% Cu²⁺/TiO₂ has the highest photocatalytic activity.3: E.coli was selected to evaluate photocatalytic antibacterial properties of 0.1% Mⁿ⁺/TiO₂ thin films. Results show that nano-Cu²⁺ /TiO₂ thin film, Mn 2+/ TiO₂ thin film and Fe 3+/TiO₂ thin films have a good inhibitory effect on E.coli. The average inhibition rate could reach up to 100%, 96.59% and 95.73% during 30 min xxx, when the UV Intensity is 5mW·cm-2.4: Nano-Cu²⁺/TiO₂ sol's photocatalysis of inactivation efficiency on Avian Influenza Virus (AIV, H9 N2) were evaluated under 365 nm UV black light. Hemagglutination tests were used to determine the change of the titer of H₉N₂. Microscope was used to observe the deformation of MDCK cells. The inactivation efficiencies of nano-Cu²⁺/TiO₂ sol on H9 N2 virus were studied by adjusting the UV intensity, the UV illumination time, and the quantity of H₉N₂ . The results show that nano-Cu²⁺/TiO₂ has a remarkable inactivation on H9 N2 virus under 365nm UV irradiation. Its inactivating rate on H₉N₂ viruses can be reached up to 100%, when the UV intensity is 0.5mW·cm-2, the quantity of H9 N2 is 0.1ml, and the UV illumination time is 2.5h. This suggested that the nano-Cu²⁺/TiO₂ sol had great potential as a kind of anti-virus agent for preventing AIV .5: Nano-Cu²⁺/TiO₂ sol's photocatalysis of inhibitory effect on Cucumber Botrytis cinerea spores'germination was studied by Microscope Counting Method. The inhibitory rates of nano-Cu²⁺/TiO₂ sol on Cucumber Botrytis cinerea spores'germination were studied by adjusting the UV intensity, UV illumination time, and the concentration of spore suspension. The experimental results show that nano-Cu²⁺/TiO₂ thin film has a certain degree of inhibitory effect on Cucumber Botrytis cinerea spores'germination. The photocatalytic inhibitory can markedly improved the UV light excitation. It's believed that inhibitory rates of spore germination had a positive correlation with the UV light intensity, UV illumination time and a negative correlation with the concentration of spore suspension. Its inhibitory rate on Botrytis cinerea spores'germination can reach 96.02%, when the UV intensity is 7.5mW·cm-2, the concentration of spore suspension is108CFU?ml-1, and the UV illumination time is 6h.6: The effects of nano-Cu²⁺/TiO₂ sol on photosynthesis and growth of cucumber were studied with the use of artificial light. The results showed that nano-Cu²⁺/TiO₂ sol can affect chloroplast pigment content, net photosynthesis rate, stomatal conductance, intercellular CO2 concentration, transpiration rate. Effects were correlated with nano-Cu²⁺/TiO₂ sol's concentration. It can promote photosynthesis and plant growth in low concentration. The optimal concentration is 0.8%.