摘要铁酸锌(ZnFe2O4)是一种尖晶石结构的间接带隙半导体,具有各方面优良的性能。 近若干年以来,由于水污染日渐加重,严重威胁到自然界中人类以及其他动植物的正常 生存;另一方面,电子产品的大量应用,使得电磁污染也日趋严重。这些问题亟需得到 解决。ZnFe2O4 为代表的铁酸盐,由于其较好的光催化和吸波性能,有望可以很好地解 决现有问题,因此受到了国内外不少研究学者的青睐。74252
本文主要研究两方面内容,一是探索一种制备 ZnFe2O4 的高效快捷的新方法—自蔓 延燃烧法,也称溶胶—凝胶自蔓延燃烧法。这种方法融合了溶胶—凝胶法和低温自燃烧 法,并兼有这两种方法的优点,得到的是高反应活性 ZnFe2O4 超细粉末。我们将得到的 ZnFe2O4 超细粉末煅烧后,发生结晶化生成 ZnFe2O4 晶体粉末,并采用 X 射线衍射
(XRD),扫描电子显微镜(SEM)表征 ZnFe2O4 超细晶体粉末。
另一方面是测定 ZnFe2O4 超细粉末的光催化性能。我们以罗丹明 B(RhB)为染料, 在 500W 氙(Xe)灯,即为可见光照射下 ZnFe2O4 催化降解罗丹明,通过每隔 30min 在 可见光分光光度计上测量一次罗丹明 B 对可见光的吸收值来研究 ZnFe2O4 超细粉末的光 催化性能。经过测试,原料中金属离子总量与燃料的比例为 1:1,煅烧温度为 400℃时, 所制得催化剂的光催化效果最好,此催化剂在光照 3h 后,对罗丹明 B 的脱色率达到 86。6%。
毕业论文关键词 铁酸锌 自蔓延燃烧法 可见光照射 光催化性能
毕 业 设 计 说 明 书 外 文 摘 要
Title Preparation of ultrafine ZnFe2O4 by self-propagating
combustion method and its synergistic catalytic performance
Abstract Zinc ferrite( ZnFe2O4 ), an indirect band gap semiconductor,possesses some excellent performances with a spinel structure。 During the past few years,the increasing water pollution has been seriously threatening to human being and other animals and plants。 On the other hand, a large number of applications of electronic products, making the electromagnetic pollution is also becoming increasingly serious。 These problems need to be solved urgently。 ZnFe2O4, as a representative ferrite, due to its better photocatalytic and wave-absorption performances, is expected to solve the existing problems, therefore, it has been favored by many researchers at home and abroad。
In this paper, two aspects were mainly investigated。 Firstly, an efficient new method was applied for the preparation of ZnFe2O4-self-propagating combustion method, also known as sol-gel self-propagating combustion method。 This method combines the sol-gel method and the low temperature self-propagating method, which is obtained by the high reaction activity of ZnFe2O4 ultrafine powder。 After ZnFe2O4 ultrafine powder was calcined, ZnFe2O4 crystal powder was formed by crystallization。 X - ray diffraction (XRD), scanning electron microscopy (SEM) was used to characterize the ZnFe2O4 crystal ultrafine powders。
Secondly, the photocatalytic activity of ZnFe2O4 crystal ultrafine powder was determined。 Rhodamine B (RhB) was used as dye pollutant。 With a 500 Watt Xe lamp, Rhodamine B was photodegraded over ZnFe2O4 under visible light irradiation。 The photocatalytic properties of ZnFe2O4 ultrafine powders were studied by measuring the absorption value of a Rhodamine B on the visible light at every 30 minutes。 According to the photocatalytic experiment, the optimal catalytic performance could be obtained with the ratio of metal ions to the fuel at 1:1 at the calcination temperature of 400 °C。 After irradiation for 3 hours over ZnFe2O4, the decolorization rate of Rhodamine B reached 86。6%。 自蔓延燃烧法制备超细ZnFe2O4及其协同催化性能:http://www.youerw.com/cailiao/lunwen_84790.html