摘 要:本文以凹凸棒土为基体,通过原位-沉积法,依次将一系列FexOy-SnO2磁性复合氧化物(r=nFe:nSn= 3:1、1:1、1:3、1:3.5、1:4、1:4.5、1:5、1:6)负载到凹凸棒土表面,制备磁分离型复合光催化剂(标记为ATT-FexOy-SnO2-r)。采用 XRD、BET、UV-vis、磁强计等分析手段对产物进行了表征,研究表明产物的包覆效果好,具有较好的磁性。以可见光催化降解对硝基苯胺为探针,研究了凹凸棒土改性前后的光催化性能,并考察了FexOy-SnO2包覆配比对其光催化性能的影响。结果表明:经过氧化物包覆改性后,凹凸棒土的光催化性能得到明显提高,而且FexOy-SnO2复合氧化物的包覆配比不同,ATT-FexOy-SnO2光催化性能不同;随着SnO2投入量的增加,ATT-FexOy-SnO2的光催化性能逐渐增强,当r= nFe:nSn =1:5时,复合材料的光催化效果最佳,光降解3h后,对硝基苯胺的降解率达81.10%;此后随着SnO2量的不断增加,复合材料的光催化性能开始降低。同时,ATT-FexOy-SnO2复合光催化材料可以用永磁铁很轻易的从反应溶液中回收、再利用。66521
毕业论文关键词:磁性光催化剂,FexOy-SnO2,凹凸棒土,可见光催化,原位-沉积法,可见光
Abstract: A magnetically recoverable Attapulgite nanocomposite photocatalyst was successfully obtained by introducing FexOy -SnO2 hybrids oxides onto its surface via an in-situ depositing technique at a low temperature of 70°C (marked as ATT-FexOy-SnO2-r). The molar ratio of r= nFe:nSn was adjusted to series of proportion (3:1、1:1、1:3、1:3.5、1:4、1:4.5、1:5、1:6) in order to achieve the best photocatalyst. The obtained samples were characterized by XRD, BET and UV-Vis measurements. It was found that FexOy-SnO2 nanocomposite particles with average size of about 10 nm were successfully introduced onto the Attapulgite fibers’ surface without obvious aggregation. Its photocatalytic removal of methyl orange under visible light radiation was also reported. Compared with ATT, ATT-FexOy, ATT-FexOy-SnO2 exhibits exceptional photocatalytic activity in visible-light degradation of 10 mg•L-1 paranitroanilinum. The photodecomposition rate of paranitroanilinum increased along with the increasing content of SnO2 in the case of r= nFe:nSn=1:5 and decreased as r< 1:5. The highest degradation rate was reached by using ATT-FexOy-SnO2 (r=1:5), which was up to 81.10% within 180 min. The ATT-FexOy-SnO2 composites could be readily recovered from the reaction solution by using a permanent magnetic bar.
Key word: Magnetically photocatalysis, FexOy-SnO2, Attapulgite, In-situ deposit technique, visible light radiation
目录
1 引言 1
2 实验部分 2
2.1 试剂和仪器 2
2.2 ATT-FexOy- SnO2复合光催化剂的制备 2
2.2.1 粗提纯凹土的制备 2
2.2.2 ATT- FexOy的制备 2
2.2.3 ATT-FexOy-SnO2光催化剂制备 3
2.3 材料表征 3
2.4 材料的光催化性能 3
3 结果与讨论 3
3.1 催化剂的表征 3
3.1.1 催化剂的XRD检测 3
3.1.2 催化剂的N2吸附-脱附等温线 5
3.1.3 催化剂的饱和磁性强度曲线 5
3.1.4 催化剂的UV-vis漫反射图谱