CDs-BOC复合催化剂可见光下活化过硫酸盐降解典型PPCPs  

CDs-BOC Nanophotocatalyst Activating Persulfate Under Visible Light for the Efficient Degradation of Typical PPCPs

作　　者：雷倩 许路 艾伟 李志敏 杨磊[1] LEI Qian;XU Lu;AI Wei;LI Zhi-min;YANG Lei(School of Environmental and Municipal Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China)

机构地区：[1]西安建筑科技大学环境与市政工程学院,西安710055

出　　处：《环境科学》2021年第6期2885-2895,共11页Environmental Science

基　　金：国家自然科学基金青年科学基金项目(51808434);陕西省科技厅自然科学基础研究计划项目(2018JQ5129)。

摘　　要：本研究通过简便的水热和煅烧两步法合成了一种新型光催化剂,该方法用碳量子点(CDs)修饰Bi OCl纳米片.制备的纳米复合材料(CDs-BOC)通过X射线衍射(XRD)、扫描电子显微镜(SEM)、高分辨率透射电子显微镜(HRTEM)、紫外-可见漫反射吸收光谱(DRS)、X射线光电子能谱(XPS)和稳态荧光光谱(PL)等手段进行了表征.结果表明,此材料成功地引入了CDs.7%CDs-BOC纳米复合材料的光吸收边界被增强至可见光区域(424 nm),并提高了光致电子-空穴对的分离效率.为了提高有机污染物降解的效果,过硫酸盐(PS)被引入了CDs-BOC光催化体系中.由于复合纳米催化剂具有出色的光催化能力,光生电子可以有效活化PS,产生更多的活性氧化物质.在可见光(λ>420 nm)照射下,20 min内可以完全去除5 mg·L^(-1)对-乙酰氨基酚(AAP).通过自由基淬灭实验和电子顺磁共振波谱(EPR),探明了此体系具有多种活性氧化物质:·OH、·SO_(4)^(-)、·O_(2)-和h^(+),并提出了降解反应机制.以上结果体现出CDs-BOC/PS体系在光催化处理水污染方面具有广阔的应用前景.A new type of CDs-BOC photocatalyst was synthesized in a convenient two-step method of hydrothermal and calcination processes.Carbon quantum dots(CDs)were used to modify Bi OCl nanosheets.The as-prepared nanocomposite was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM),UV-vis diffuse reflectance spectroscopy(DRS),X-ray photoelectron spectroscopy(XPS),and photoluminescence spectroscopy(PL),which showed that CDs were successfully introduced.The absorption edge of 7%CDs-BOC nanocomposite was broadened to the visible light region(424 nm),and the charge separation efficiency was remarkably improved.To improve the degradation efficiency of organic pollutants,persulfate(PS)was also introduced into the system.Due to the excellent photocatalytic ability of the nanocatalyst,the photogenerated electrons can effectively activate the PS to produce more reactive oxidizing species(ROS).Under visible light(λ>420nm)irradiation,5 mg·L^(-1)acetaminophen(AAP)can be completely removed within 20 min.Via radical quenching experiments and electron paramagnetic resonance spectroscopy(EPR),the major ROS are determined to be·OH,·SO_(4)^(-),·O_(2)-,and h^(+),and the photodegradation mechanism is proposed.The excellent photocatalytic performance of the CDs-BOC/PS system shows broad practical potential for wastewater treatment.

关 键 词：可见光催化 过硫酸盐活化 碳量子点 活性氧化物质 对-乙酰氨基酚(AAP) 

分 类 号：X703.1[环境科学与工程—环境工程]