摘要分别以NaOH与NH3•H2O/NH4HCO3两种沉淀剂体系采用化学共沉淀法制备BiFeO3前驱体，进过煅烧获得BFO纳米粉体。研究不同pH滴定终点、复合沉淀剂混合配比、煅烧条件对于单相BiFeO3粉体晶型结构、晶粒大小、粒度分布及甲基橙光催化降解性能的影响。结果表明：在NAOH体系中pH在9-11之间，600℃煅烧2h可获得单相BiFeO3粉体，所有BFO粉体均具有光催化性能，且随催化时间催化降解率逐渐提高，其中pH=10、550℃煅烧2h样品，5小时降解率达到了62.93%。在NH3•H2O/NH4HCO3体系中体积比1：2、600℃煅烧2h可获得单相BiFeO3粉体，所有BFO粉体均具有光催化性能，且随催化时间催化降解率逐渐提高，其中体积比1：2、550℃煅烧2h和600℃煅烧1h样品，5小时降解率均达到了54.20%。42724

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

Abstract

We use NaOH and NH3·H2O/NH4HCO3 two precipitation agent systems to prepare BiFeO3 by chemical co-precipitation method.Then we get BFO powder after calcining. Researching Single phase BiFeO3 powder crystal structure, grain size, grain size distribution and the effect of photocatalytic degradation performance in different pH titration, different Mixture ratio of compound precipitator, different calcining conditions.The results showed that in NaOH system ,we can get single phase BiFeO3 powder when pH is between 9-11 and calcining in  600℃for 2 hours. All BFO powders had light catalytic properties,and the degradation rate increased with the catalytic time.Among them, the degradation rate of the sample which was pH=10 ,calcined at 550℃ for 2 hours, is 62.93% after 5 hours.In NH3·H2O/NH4HCO3 system,we can get single phase BiFeO3 powder when the mixture ratio of compound precipitator is 1:2 and calcining in  600℃for 2 hours. All BFO powders had light catalytic properties and the degradation rate increased with the catalytic time.Both the degradation rate of the one mixture ratio is 1:2 and calcining in  550℃for 2 hours,and the one mixture ratio is 1:2 and calcining in  6000℃for 1 hours is 54.20%.

Key words:  Ferrite ; Chemical co-precipitation method;  Bismuth ferrite powder;  Photocatalytic activity;  Multi iron material; 

目  录

1 文献综述 4

1.1 单相BiFeO3材料 4

1.2 BiFeO3的研究现状 5

1.3 BiFeO3的制备方法 6

1.3.1 固相反应法 6

1.3.2 水热合成法 6

1.3.3溶胶－凝胶法 7

1.3.4 化学共沉淀法 8

1.4 BiFeO3的特性 9

1.4.1 BiFeO3的电学性质 9

1.4.2 BiFeO3的磁学性质 10

1.4.3 BiFeO3的光催化性质 11

1.5 光催化 11

1.5.1 催化和光催化剂 11

1.5.2 半导体光催化反应过程 12

1.5.3 影响光催化活性的内因 13

2 实验内容 16

2.1 实验原料和试剂 16

2.2 实验设备 16

2.3 实验流程 17

2.4 实验方法 17

2.4.1 NaOH共沉淀体系BFO前驱体合成