几种铋基功能纳米材料的制备及性能研究

发布时间：2018-10-17 19:52

【摘要】：发展材料新合成方法对于研发新产品和拓展材料新性能均具有重要的意义。传统的固相合成法由于烧结温度高、反应时间长、能耗高、样品颗粒大等缺点,很难满足人们对新型材料越来越高的要求。尤其是纳米材料的迅速发展为探索高效合成新方法提出了挑战。本论文就纳米材料的“绿色”合成问题展开了系列研究,采用共沉淀法和低温熔盐法制备了三种含铋功能纳米材料,并系统研究了它们的性能。主要内容如下:第一部分:结合共沉淀法和固相烧结的方法制备了不同铋离子浓度掺杂的Ca_2Sb_2O_7:xBi~(3+)粉体,通过XRD、SEM、XPS、FTIR以及PL等手段对该荧光材料进行结构表征和相关性能测试。结果表明所制备的Ca_2Sb_2O_7:xBi3样品主要为球形颗粒,粒子尺寸约20-40 nm。室温条件下,利用337 nm的紫外光激发,样品显示强烈的蓝发光,发光峰位于441 nm。值得注意的是,该发射峰由两部分叠加而成,发射峰位置分别位于432 nm及456 nm。分析显示,两个发光峰可能来源于不同晶格位置的Bi~(3+),即Bi~(3+)(4a)和Bi~(3+)(4d)。第二部分:探索了一种新的低温熔盐法体系,并利用该方法制备了Na_3Bi(PO_4)_2纳米材料,优化了相应的工艺条件:反应温度为180℃,反应时间12 h,反应物比例1:4。之后再将Eu~(3+)引入到该体系中,系统研究了铕离子的掺杂对样品形貌特征及发光性能的影响,并研究了其发光机理。第三部分:通过低温熔盐法合成多铋光催化纳米材料NaBi_7P_2O_(16),所制样品为纯相,结晶度较高,形貌呈片状,其禁带宽度为3.44 eV。通过光降解甲基橙实验系统评估了纳米NaBi_7P_2O_(16)的光催化性能。结果显示NaBi_7P_2O_(16)纳米片具有很好的光催化活性,30分钟内,甲基橙的光降解率可达到97%。并且该材料具有较好的稳定性,是一种非常有前景的光催化材料。
[Abstract]:It is of great significance to develop new synthetic methods of materials for the development of new products and new properties of materials. Due to the disadvantages of high sintering temperature, long reaction time, high energy consumption and large sample size, the traditional solid state synthesis method is difficult to meet the increasing demand for new materials. In particular, the rapid development of nanomaterials poses a challenge for exploring new methods of efficient synthesis. In this paper, a series of studies on the "green" synthesis of nanomaterials were carried out. Three kinds of bismuth functional nanomaterials were prepared by co-precipitation method and low temperature molten salt method, and their properties were systematically studied. The main contents are as follows: in the first part, Ca_2Sb_2O_7:xBi~ (3) powders doped with different bismuth ion concentrations were prepared by means of coprecipitation and solid-state sintering. The structure and properties of the phosphor were characterized by XRD,SEM,XPS,FTIR and PL. The results showed that the Ca_2Sb_2O_7:xBi3 samples were mainly spherical particles, and the particle size was about 20-40 nm.. At room temperature, the samples were excited by UV light at 337 nm. The samples showed strong blue luminescence with a peak at 441 nm.. It is worth noting that the emission peak is superimposed by two parts, which are located at 432 nm and 456 nm., respectively. The results show that the two peaks may originate from Bi~ (3) at different lattice positions, that is, Bi~ (3) (4a) and Bi~ (3) (4d). The second part: a new low temperature molten salt system was explored, and Na_3Bi (PO_4) _ 2 nanomaterials were prepared by this method. The corresponding process conditions were optimized as follows: reaction temperature 180 鈩，

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