摘要
采用一步水热法制备纳米Ag-SrTiO_3可见光催化剂,利用X射线衍射、X射线光电子能谱、扫描电镜和紫外可见光吸收光谱等对Ag-SrTiO_3的组成、形貌及吸光性进行表征,通过对四环素(TC)的降解实验研究了其在可见光下的光催化活性和稳定性,并进一步通过光致发光光谱、电子自旋共振和自由基捕获实验探究了其对TC的降解机制。结果表明,Ag+可成功掺杂到SrTiO_3中,且Ag-SrTiO_3的吸收光较纯SrTiO_3明显发生红移;当AgNO_3与Sr(NO_3)_2的摩尔分数为3%时,制备的Ag-SrTiO_3对TC的光降解效果最好,120min内降解率可达79.63%,较纯SrTiO_3提高13倍,光催化降解TC反应过程符合准一级动力学模型,且重复使用8次后仍具有较高光催化活性;Ag-SrTiO_3中Ag+捕获了SrTiO_3产生的电子,有效抑制了电子和空穴的复合概率,从而增加其光催化活性,且其主要活性物种为·O_2~–。
Nano-Ag-SrTiO3 visible-light catalyst was prepared by one-step hydrothermal method.Composition,morphology and structure,visible-light absorption performance of Ag-SrTiO3 were characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),and ultraviolet visible absorption spectra(UV-vis),respectively.Photocatalytic property and stability of Ag-SrTiO3 in visible-light were studied by tetracycline(TC)degradation experiment,and its degradation mechanism for TC was also investigated by photoluminescence spectra(PL),electron spin resonance(ESR)analysis and free radical capture experiment.The results showed that Ag+could be well doped in SrTiO3,and the absorption spectra of Ag-SrTiO3 significantly redshifted compared with pure SrTiO3.The photocatalytic property of Ag-SrTiO3 for TC degradation was optimal while the molar ratio of AgNO3 and Sr(NO3)2 was 3%,and its degradation rate could reach 79.63%within 120min,13 times higher than pure SrTiO3.Furthermore,TC degradation of Ag-SrTiO3 showed a good compliance with the pseudo-first-order kinetic model.Ag-SrTiO3 still had excellent photocatalytic degradation activity after 8 times reuse.Electronics generated in SrTiO3 was captured by Ag+in Ag-SrTiO3.The compound probability of electron and hole could be effectively restrained,which resulted in the increase of photocatalytic properties.The main active species of Ag-SrTiO3 was·O2–.
作者
曹丽丽
蒋善庆
凌泽玉
汪楚乔
许霞
王利平
CAO Lili;JIANG Shanqing;LING Zeyu;WANG Chuqiao;XU Xia;WANG Liping(School of Environmental&Safety Engineering,Changzhou University,Changzhou 213164,Jiangsu,China)
出处
《化工进展》
EI
CAS
CSCD
北大核心
2018年第11期4500-4508,共9页
Chemical Industry and Engineering Progress
基金
国家自然科学基金(21477050
21607017)
常州国际科技合作计划(CZ20140017)项目
作者简介
曹丽丽(1993—),女,硕士研究生,研究方向为环境功能材料制备及难降解有机物处理;通讯作者:王利平,教授,硕士生导师,研究方向为水资源及饮用水安全保障技术。E-mail:wlp@cczu.edu.cn。
