Study On Preparation And Photocatalytic Properties Of Nickel, Zinc, Titanium-Based Oxide Powders

In this dissertation, the photocatalytic properties of NiO, ZnO, TiO2 were discussed by photodegradation of methyl orange. The sol-gel preparation methods and the mechanism analysis of the new photochemical catalysis material were explored.NiO powders were synthesized by two different sol-gel methods. Their advantages and disadvantages were compared. The photocatalytic effect and mechanism analysis of the pure NiO treated with pipe heater, doping Na+, Ag+, Li+ and vacuum sintering were studied. The results show that Ni will separate out in NiO doped with Na+ and reduced the photocatalytic activity of NiO. Ag+ doping did not increase the photocatalytic activity of NiO. When the amount of Li+ dopant is less than or eaual to 0.075, the photocatalytic activity of NiO increase effectively and lithium optimum doping amount is 0.025. Its photodegradtion rate was higher 13% than the NiO treated with pipe heater. The optimum vacuum level is 0.5Pa in the vacuum sintering. its photodegradtion rate was higher 10% than the NiO treated with pipe heater.The sol-gel preparation technology of TiO2 and Mo6+ doped TiO2 were studied, the key factors influencing the process were summariazed and the links between the calcination temperature, crystal structure and the photocatalytic activity were examined. The results show that the crystal transformation was suppressed with Mo6+ dopant.The photocatalytic activities increase when NiO mixed with Li0.025Ni0.975O.ZnO powder was prepared by sol-gel method. The sample was characterized by thermal analysis ,X-ray diffraction. The degradation rate of ZnO with the amount of 0.1g/L was 76.5% in 4h. The maxmum photodegradation rate of composite powder ZnO/NiO reached 89.675% when the mass ratio was 2:1. The maxmum photodegradation rate of composite powder ZnO/Ag0.025Ni0.975O reached 90.95% when the mass ratio was 1:1. The maxmum photodegradation rate reached 93.099% when the mass ratio between ZnO and NiO treated with 0.5Pa vacuum level was 2:1. The composite powder of ZnO/Li0.025Ni0.975O, with the mass ratio of 1:1, reached the best photocatalysis property, 97.572%. The final test result indicates that the composite powder of ZnO/Li0.025Ni0.975O had the best of photocatalytic property, 98.1%, when the amount was 0.2g/L and the mass ratio was 1:1.