Preparation Of Nano ZnO Particles By Microwave Assisted Hydrothermal Method With Researching Its Photocatalytic Property And The Toxicity To Microalgae

In this paper, Using Zn (NO3)2·6H2O and NaOH as raw materials, microwave hydrothermal method as the preparation method to obtain the nano zinc oxide crystal powder. Studying the microwave reaction time, temperature, sodium hydroxide, and concentration of NaOH and the influence of different surfactants to prepare the nano zinc oxide crystal system. We determined the process which the diameter of the preparation of nanometer zinc oxide was the minimum and the yield was the highest. Morphology and structure of nano zinc oxide were characterized by XRD, TEM and other analytical means at the same time. Using the nano oxide crystal particles which were prepared in the optimum condition doing the inquiry about its photocatalytic property and its toxic effect of Chlorella inquiry, we get the following valuable achievements:1. Because of microwave hydrothermal method, we get the high purity nano Zinc Oxide crystals in the 5 min, while it is the shortest time;2. The best reaction temperature is 15 min; the optimum concentration ratio of zinc ion and hydroxide ion is 1.0; the optimal reaction temperature is 120 ℃; add about 3.6×10-3 mol/L SDBS as surfactant. Under these optimum reaction conditions, the obtained ZnO crystals is the minimum size which the yield is also high;3. The optimal addition amount of nano ZnO is 200 mg to 100mL helianthin which concentration is 10 mg/L. It can be degraded above 90% in one hour.4. Zinc ion and its effect of nano played certain toxicity together. The more nano ZnO, the stronger toxicity. When the concentration of zinc ion reached to 50 mg/L, the growth of Chlorella vulgarisms has largely stalled. The rotary speed of incubator also affects the toxic effect in certain. Illumination condition is a very important influence factors to the growth of Chlorella pyrenoidosa.