The Study On Preparation And Photocatalysis Of Nanometer Zinc Oxide

ZnO is a kind of important semiconductor material,its bulk material's energy gap is 3.2eV,as a kind of important photocatalyst,ZnO was one of several semiconductors which could realize quantum size effet,which gained people comprehensive research inrcent years.But photocatalytic efficiency of nano-zinc oxide is lower,it is hard to apply in the engineering.So how to raise the photocatalytic efficiency will be one of the most important in the future.In the first part:The diethanol amine modified of nano-ZnO was prepared by acetic acid as a precursor,oxalic acid as complexing agents,diethanol amine as modifiers,ethanol as solvent.The samples were characterized by means of wide-angle X-ray diffraction,and BET.The appropriate conditions for preparing the diethanol amine modified of nanometer ZnO can be concluded from the experiment and listed as follows:the mole ratio of modifier and zinc is 0.5:1,the gelling temperature is 80?,the gel aging time is 1.5 h,Zn(Ac)2·2H2O solution is slowly distributed to(COOH)2·2H2O solution,calcinations temperature is 500?.Photocatalytic conditions:When the catalyst content is 0.15 g,response time is 1h,themethyl orange was completely degradated.According to the XRD results,it is concluded that the product is hexagonal wurtzite structure ZnO with fine crystallization.In the second part:A novel photocatalytic composite material ZnO/LQ-1 was prepared using sol-gel method.Taking the degradation of methyl orange as model reaction.The effects of the amount of doped LQ-1,gelling temperature,gelaging time,calcination temperature,and calcination time on the photocatalytic reaction were investigated.the optimum preparation conditions was determined:the mole ratio of LQ-1 and zinc is 0.5:1,gelling temperature is 80?,the gel aging time is 1.5 h,calcinations temperature is 600?,calcinations time is 3 h.the suitable condition of photocatalys is:When the catalyst content is 0.1 g,response time is 1h,the methyl orange was completely degradated.In the third part:The polyethylene glycol modification of nanometer ZnO was prepared.The prepared Nano-ZnO was systematically characterized by XRD,TG-DTA and SEM.Taking Benzaldehyde was synthetized benzyl alcohol as model reaction.The effects of solvent,photocatalytic time,catalyst amount,pH,oxidant on the photocatalytic reaction were investigated.The result shows the best experimental condition was that LQ-2 as solvent,illumination 4 h,catalytic amount of 0.01,pH of 9,the conversion of benzylvalcoho and selectivity of benzaldehyde are 39.17%and 82.99%,respectively.