【摘要】：發(fā)展材料新合成方法對于研發(fā)新產(chǎn)品和拓展材料新性能均具有重要的意義。傳統(tǒng)的固相合成法由于燒結溫度高、反應時間長、能耗高、樣品顆粒大等缺點,很難滿足人們對新型材料越來越高的要求。尤其是納米材料的迅速發(fā)展為探索高效合成新方法提出了挑戰(zhàn)。本論文就納米材料的“綠色”合成問題展開了系列研究,采用共沉淀法和低溫熔鹽法制備了三種含鉍功能納米材料,并系統(tǒng)研究了它們的性能。主要內容如下:第一部分:結合共沉淀法和固相燒結的方法制備了不同鉍離子濃度摻雜的Ca_2Sb_2O_7:xBi~(3+)粉體,通過XRD、SEM、XPS、FTIR以及PL等手段對該熒光材料進行結構表征和相關性能測試。結果表明所制備的Ca_2Sb_2O_7:xBi3樣品主要為球形顆粒,粒子尺寸約20-40 nm。室溫條件下,利用337 nm的紫外光激發(fā),樣品顯示強烈的藍發(fā)光,發(fā)光峰位于441 nm。值得注意的是,該發(fā)射峰由兩部分疊加而成,發(fā)射峰位置分別位于432 nm及456 nm。分析顯示,兩個發(fā)光峰可能來源于不同晶格位置的Bi~(3+),即Bi~(3+)(4a)和Bi~(3+)(4d)。第二部分:探索了一種新的低溫熔鹽法體系,并利用該方法制備了Na_3Bi(PO_4)_2納米材料,優(yōu)化了相應的工藝條件:反應溫度為180℃,反應時間12 h,反應物比例1:4。之后再將Eu~(3+)引入到該體系中,系統(tǒng)研究了銪離子的摻雜對樣品形貌特征及發(fā)光性能的影響,并研究了其發(fā)光機理。第三部分:通過低溫熔鹽法合成多鉍光催化納米材料NaBi_7P_2O_(16),所制樣品為純相,結晶度較高,形貌呈片狀,其禁帶寬度為3.44 eV。通過光降解甲基橙實驗系統(tǒng)評估了納米NaBi_7P_2O_(16)的光催化性能。結果顯示NaBi_7P_2O_(16)納米片具有很好的光催化活性,30分鐘內,甲基橙的光降解率可達到97%。并且該材料具有較好的穩(wěn)定性,是一種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，

本文編號：2277776