节点文献
(010)晶面暴露的Bi2MoO6纳米片对土霉素和四环素的可见光催化降解
Photocatalytic degradation of oxytetracycline and oetracycline by Bi2MoO6 nanosheets with(010) facets exposed to visible light
【摘要】 以(010)晶面暴露的Bi2MoO6纳米片作为光催化剂,通过改变溶液pH值、催化剂用量及目标降解物的初始浓度等考察Bi2MoO6纳米片对土霉素(Oxytetracycline,OTC)和四环素(Tetracycline,TC)在可见光下降解效果的影响;通过加入不同的自由基清除剂来考察光催化过程的机理。结果表明:光催化剂对OTC和TC的降解效果会因其在溶液中的存在形式不同而改变,随着溶液pH值的升高OTC与TC会发生逐级电离。在最佳pH值(pH=11)条件下,可见光辐照1h后,OTC与TC分别降解42.1%和58.8%(催化剂质量浓度为1.4g/L)。OTC和TC的光催化降解动力学研究表明,其降解过程符合伪一级动力学方程,其降解动力学常数分别为0.006 64min-1和0.008 45min-1。光催化降解机理的研究表明,空穴是主要的活性物质,其原因可能是在pH值为11时,大量的OTC和TC被吸附在光催化剂表面,有利于光生电子从光催化剂迁移至目标降解物。
【Abstract】 The photocatalytic degradation of two widely used antibiotics including Oxytetracycline(OTC)and Tetracycline(TC)in the aqueous suspension containing Bi2MoO6 nanosheets with(010) facets exposed to visible light was studied.The effects of catalyst amount,initial pH,and initial concentrations of substrates on the rates of photocatalytic degradation were investigated.The radical scavengers were added into the reaction solution to evaluate the activities of the free radicals.Results showed that pH significantly affected the degradation of OTC and TC.The maximum removal rates of OTC and TC were obtained at pH 11.0with concentration of Bi2MoO6 of 1.4g/L and initial concentration of substrates of 20mg/L.Under these conditions,42.1% of OTC and 58.8% of TC were degraded under visible light for 60minutes.The disappearance of these two compounds followed a pseudo-first-order kinetics based on the Langmuir-Hinshelwood(L-H)model.The rate constants for OTC and TC were0.006 64min-1 and 0.008 45min-1,respectively.The surface reaction on Bi2MoO6 played an important role in degrading OTC and TC.The further study of reactive oxygen species(ROSs)showed that the photo-generated hole(h+)was mainly responsible for the degradation of OTC and TC.
【Key words】 Bi2MoO6; visible light; photocatalytic degradation; Oxytetracycline; Tetracycline;
- 【文献出处】 华中农业大学学报 ,Journal of Huazhong Agricultural University , 编辑部邮箱 ,2014年05期
- 【分类号】O643.32;X505
- 【被引频次】5
- 【下载频次】314