铋系光催化材料的制备及其性能研究
探究了KOH浓度、矿化剂KNO3、分散剂PEG-4000对BiFeO3的影响，实验表明，KOH浓度为2、8和12M时，产物都为纯相BiFeO3。随KOH浓度的增加，得到的BiFeO3晶体由不规则颗粒向立方型小颗粒团聚体过渡。此外，KNO3和PEG-4000的引入对产物的种类、形貌及光催化性能无太大影响。
研究了两种水热条件对Bi25FeO40的结构和性能的影响。实验发现KOH浓度为2mol/L、160℃下反应24h，当投加KNO3后得到纯相Bi25FeO40颗粒；当投加PVA和KNO3后，可以制备颗粒分散、粒径在2μm的立方型Bi25FeO40的纯相晶体。与所制备的BiFeO3相比，具有更好的可见光催化降解亚甲基蓝的效率。8403
关键词 铁酸铋 BiFeO3 Bi25FeO40 水热法 可见光催化
毕业设计说明书（论文）外文摘要
Title Synthesis and Characterization of Photocatalytic Materials of Bi Family
Abstract
Bismuth ferrite is a novel visible light photocatalyst. BiFeO3 and Bi25FeO40 particles were synthesized via a facile hydrothermal process. The as-prepared samples were characterized by X-ray diffraction and scanning electron microscopy. The photocatalytic activity of the as-prepared samples were evaluated by the degration of MB.
The effect was studied on the properties of BiFeO3 particles of the KOH concentration and the addition of KNO3 or PEG. The results show that single phase BiFeO3 particles were synthesized with the KOH concentration of 2M, 8M and 12M. With the increase of concentration, the morphologies of the as-prepared BiFeO3 crystals change from irregular particles towards aggregates of cubic-shaped crystals. Besides, the addition of KNO3 or PEG weakly affects the morphology and the photocatalytic activity of BiFeO3 particles.
Comparing two hydrothermal processes under different conditions ,the results show that single phase Bi25FeO40 powder was synthesized at 160℃ for 6h using KOH of 2M, with the addition of KNO3. Well dispersed pure cubic-shaped Bi25FeO40 crystals were synthesized with the addition of KNO3 and PVA. Compared with the as-prepared BiFeO3 particles, the Bi25FeO40 particles show higher photocatalytic activity.
Keywords Bismuth ferrite, BiFeO3, Bi25FeO40, hydrothermal process, visible light photocatalysis
目次
1. 绪论 1
1.1 可见光催化氧化技术 1
1.2 常见光催化剂 1
1.2.1 TiO2 1
1.2.2 含铋复合氧化物光催化剂 2
1.3 铁酸铋粉末的制备方法 2
1.3.1 高温固相法 3
1.3.2 水热法 3
1.3.4 溶胶-凝胶法 4
1.3.5 其他方法 4
1.4 水热法制备铁酸铋材料的影响因素 5
1.4.1 反应时间 5
1.4.2 反应温度 5
1.4.3 反应体系碱度 5
1.4.4 矿化剂 6
1.4.5 分散剂 7
1.5 铁酸铋光催化性能的研究进展 7
1.6 本课题研究内容 9
2. BiFeO3的水热合成、表征及其光催化性能的研究 9
2.1 实验部分 9
2.1.1 实验原理 9
2.1.2 实验药品与仪器 10