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摘要本文以 NaOH 作为沉淀剂，采用化学共沉淀法制备了 BiFeO3 粉体。用 X 射线 衍射（XRD）、扫描电镜（SEM）等分析手段对 BiFeO3 粉体的物相、结构、形貌等 进行了表征，研究了 NaOH 浓度、煅烧温度和时间对于 BiFeO3 粉体的晶型结构和 晶粒大小的影响；通过测定 BFO 粉体对目标污染物的光催化降解率，考察了 NaOH 浓度、BFO 添加量、污染物种类和浓度等因素对 BFO 可见光催化效果的影响。实 验结果表明：且当 NaOH 浓度为 5mol/l、煅烧温度为 600℃，煅烧时间为 1~2h 时可得到纯相 BiFeO3 粉体。该 BiFeO3 为 R3c 结构，晶粒尺寸为 39.3-44.0nm，BFO 粉体为表面粗糙的球形颗粒，颗粒直径为 5-15μm。该粉体对低浓度甲基橙（MO） 具有很好的催化效果，在 100mL10mg/L 的 MO 溶液中添加 0.1g 的 BFO-1M 粉体， 添加少量 H2O2，光照 2.5h 时降解率已达 93.97%。此外，BFO 粉体对亚甲基蓝（MB） 和罗丹明 B（Rh）具有更优异的可见光催化效果，光照 2h，其对 Rh 和 MB 光催化 降解率分别为 99.06%和 91.86%。 66249
毕业论文关键词： 铁氧体；化学共沉淀法；铁酸铋粉体；光催化性能;降解；甲基橙； 废水处理
Abstract In this paper, BiFeO3 powder was prepared by chemical co-precipitation method using NaOH as precipitant. The phase, structure and morphology of BiFeO3 powder were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effects of NaOH concentration, calcination temperature and time on the crystal structure of BiFeO3 And the effects of NaOH concentration, BFO addition amount, pollutant type and concentration on the photocatalytic activity of BFO were investigated by measuring the photocatalytic degradation rate of BFO powder to target pollutants. The experimental results show that pure phase BiFeO3 powder can be obtained when the concentration of NaOH is 5mol/L, the calcination temperature is
600℃ and the calcination time is 1 ~ 2h. The BiFeO3 is of the R3c structure, the
grain size is 39.3-44.0nm, the BFO powder is the surface rough spherical particles, the particle diameter is 5-15μm. The powder had a good catalytic effect on low concentration of methyl orange (MO). 0.1 g of BFO-1M powder was added to 100 mL of 10 mg/L MO solution, and a small amount of H2O2 was added. The degradation rate was 93.97 %. In addition, BFO powder had more excellent photocatalytic effect
on methylene blue (MB) and rhodamine B (Rh). The photocatalytic degradation rate of Rh and MB was 99.06% and 91.86%, respectively.
Key words: Ferrite；Chemical co-precipitation method; Bismuth ferrite powder; Photocatalytic activity; Degradation; Methyl Orange (MO); Wastewater treatment
目录
1.1 BiFeO3 材料简介 5
1.2 BiFeO3 的研究现状 . 6
1.3 BiFeO3 的制备 .. 7
1.3.1 水热合成法 7
1.3.2 化学溶液沉淀法 .. 8
1.3.3 溶胶-凝胶法 .. 8
1.3.4 固相反应法 .. 10
1.4 BFO 纳米粉体的光催化性质 . 10
1.4.1 半导体材料的光催化机理 .. 10
1.4.2 影响光催化活性的内因 12
1.4.3 影响光催化活性的外因 . 12
2 实验内容 .. 15
2.1 实验原料和试剂 .. 15
2.2 实验设备 .. 15
2.3 实验流程 .. 16
2.4 测试方法.. 17
2.4.1 X 射线衍射 .. 17
2.4.2 扫描电镜（SEM） 17
2.4.3 可见光催化降解有机污染物 17
3 结果与讨论 19
3.1 工艺条件对 BFO 粉体结构及晶粒尺寸的影响.. 19