摘 要:本文通过水热法和原位沉积法,以凹凸棒土为催化剂载体,分别将CoFe2O4和BiOBr包覆在凹凸棒土上制成一系列不同配比(r= n Bi/(nCo+nBi)=0。5、0。85、0。95)的复合光催化剂(产物标记为ATT-CoFe2O4-BiOBr)。采用XRD,BET,SEM,UV-vis等分析手段对产物进行了表征。结果表明改性后的产物的包覆效果好、比表面大。以可见光光催化降解甲基橙为探针,研究了凹凸棒土改性前后的光催化性能。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,当r=0。85时复合材料的光催化效果最佳,光降解3h后,对20mg/L的甲基橙降解率达到94。11%。该催化剂在循环降解2次后,降解率仍然保持在80。23%。75902
毕业论文关键词:CoFe2O4-BiOBr,可见光催化,凹凸棒土,水热,原位沉积法,甲基橙
Abstract: In this article, we took the attapulgite as a substrate by hydrothermal method and In-situ deposite method。 A series of photocatalyst(r= n Bi/(nCo+nBi)=0。5、0。85、0。95) was successfully obtained by introducing CoFe2O4 and BiOBr onto its surface(marked as ATT-CoFe2O4-BiOBr)。 The obtained samples were characterized by XRD, SEM, BET, UV-Vis measurements。 Results showed that the surface morphology of the original attapulgite was effectively reformed and the specific surface area was successfully improved。Visible light photodecomposition of methyl orange was used as the model system to investigate the Attapulgite photocatalic activity before and after coating modification。 It was found that the photoactivity of Attapulgite was obviously improved after coating modification。 The best photocatalyst of ATT-CoFe2O4-BiOBr was obtained when the r was adjusted to 0。85 and the decomposition rates of methyl orange achieved to 94。11%。 Moreover, ATT-CoFe2O4-BiOBr could be readily recovered and the degradation ratio maintains 80。23 % after 2 cycles。
Keyword: CoFe2O4-BiOBr, Visible light photodecomposition, Attapulgite, Hydrothermal, In-situ deposite,Methyl orange
目 录
1 前言 2
2 实验内容 3
2。1 试剂和仪器 3
2。2 复合光催化剂的制备 3
2。3 材料表征 4
2。4 材料的光催化性能 4
3 结果与讨论 5
3。1 催化剂的表征 5
3。2 催化剂的催化性能研究 10
结 论 14
参 考 文 献 15
致 谢 17
1 前言
现代工业的快速发展,含有有毒、致癌污染物废水的大量排放,严重威胁着人类的健康。半导体光催化技术作为一种新的环境净化技术,是近十几年来兴起的一门新技术,目前在污染治理技术领域和能源开发方面的研究很活跃。它是指通过照射半导体光催化剂使其价带上的电子受到激发后跃迁到导带,并分别在价带和导带上形成光生空穴和电子,在水中产生氧化能力极强的羟基自由基,从而将污染物氧化降解[ ]为无机小分子CO2,H2O,HX及矿化物等,以达到彻底降解污染物而又不带来二次污染的目的。 许多用其他方法难以去除的有机污染物,比如氯仿、有机磷化合物、多氯联苯、多环芳烃等都可以利用光催化反应去除。因此,光催化技术是一种在能源和坏境领域有着重要应用前景的绿色技术。论文网