微波水热法制备纳米ZnO及其光催化性能和对小球藻毒性的研究

发布时间：2018-03-05 00:15

  本文选题：微波水热法　切入点：纳米氧化锌　出处：《江西科技师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文以六水合硝酸锌(Zn(NO3)2·6H2O)及氢氧化钠(NaOH)作为原料,微波水热法作为制备方法以获得纳米氧化锌晶体粉末。其中系统地考察了微波反应的时间、温度、氢氧化钠的浓度以及不同的表面活性剂对制备所得纳米氧化锌晶体形貌尺寸的影响,确定了制备最小粒径纳米氧化锌及产率最高时的反应工艺条件,同时结合XRD、TEM等测试分析手段,对纳米氧化锌的形貌结构进行了表征。将在研究所得最佳工艺条件下所制备的纳米氧化晶体粒子进行其光催化性能的探究,以及其对小球藻毒性效应的探究,得到如下有价值的成果：1.使用微波水热法最短可在5 mmin内使得粒子结晶而形成高纯度的纳米氧化锌晶体；2.分别得到了最佳反应温度为15 min,锌离子与氢氧根离子的最佳浓度比为1.0,微波水热法制备纳米氧化锌的最佳反应温度为120℃,加入约3.6×10-3mol/L的十二烷基苯磺酸钠作为表面活性剂,在这些反应条件下,制备所得到的氧化锌晶体的尺寸为最小尺寸,且产率较高。3.在当时的外界太阳光照条件下,对于100 mL浓度为10 mg/L的甲基橙溶液,纳米氧化锌的最佳添加量为200 mg,在一个小时内就能够使所测甲基橙的降解率达到90%以上。4.纳米氧化锌对小球藻的致毒机理,是由于锌离子作用于小球藻使其受到毒性影响,同时纳米氧化锌粉末的纳米效应也对小球藻起到了一定的毒性作用。纳米氧化锌加入的量越大对小球藻的毒性越强,当纳米氧化锌的添加量使得锌离子的浓度到达50 mg/L时,小球藻的生长就已基本停滞。实验中培养箱的转速也在一定程度上影响了纳米氧化锌对小球藻的作用。光照条件是影响小球藻生长的一个很重要的要素。
[Abstract]:In this paper, nanocrystalline zinc oxide powder was prepared by microwave hydrothermal method with zinc nitrate hexahydrate zinc nitrate 2 路6H 2O and sodium hydroxide sodium hydroxide as raw materials. The time and temperature of microwave reaction were systematically investigated. The effects of concentration of sodium hydroxide and different surfactants on the morphology and size of ZnO nanocrystalline were studied. The reaction conditions for the preparation of nanocrystalline ZnO with the smallest particle size and the highest yield were determined. At the same time, the morphology and structure of nanometer zinc oxide were characterized by means of XRD- TEM. The photocatalytic properties of nano-oxidized crystal particles prepared under the optimum technological conditions were investigated. And its toxic effects on Chlorella vulgaris, The results are as follows: 1. The microwave-hydrothermal method can crystallize the particles within 5 mmin to form high purity ZnO crystal 2. The optimum reaction temperature is 15 mins, the optimum reaction temperature of zinc ion and hydroxide ion is obtained. The optimum concentration ratio is 1.0, and the optimum reaction temperature is 120 鈩，

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