摘要
为了提高ZnO对偶氮染料污染物的光催化降解效率,以AgCl和GO(氧化石墨烯)作为改性剂,通过水热法和化学沉积法制备了AgCl/ZnO/GO光催化材料,采用XRD、SEM、XPS、UV-Vis方法对材料的物相组成、微观形貌及光学特性进行表征;以MO(甲基橙)为目标污染物探究其在可见光下的催化降解性能,考察AgCl含量、催化剂投加量、pH对其可见光催化活性的影响.结果表明:①AgCl的沉积和GO的负载增强了ZnO对可见光的响应能力提高了光生电子-空穴产生、分离效率同时增加了材料的分散性及其对MO的吸附率,因此AgCl/ZnO/GO光催化材料对MO有良好的可见光催化降解效率.②AgCl/ZnO/GO对MO的催化降解效率随着AgCl含量的增加而增加,随着催化剂投加量的增加呈先增后降的趋势,溶液pH对其降解效果有一定影响,但不显著.③当AgCl/ZnO(二者物质的量的比)为2:1、AgCl/ZnO/GO投加量为70 mg、pH为7、室温下经过可见光照射50 min后,AgCl/ZnO/GO对质量浓度为10 mg/L的MO的降解率可达98.93%;此外,该催化剂重复使用4次对MO仍具有88%的去除率,显示出良好的稳定性.因此,AgCl/ZnO/GO是一种高效、稳定的可见光光催化剂在废水净化方面具有良好的应用前景.
AgCl/ZnO/GO photocatalysts were successfully synthesized by a facile multistep route,hydrothermal reaction and then chemical deposition.The prepared photocatalysts exhibited effective degradation performance of organic contaminants.The structure,morphology,composition,optical,and photocatalytic properties of the composite samples were characterized by X-ray、diffraction(XRD),scanning electron microscopy(SEM),X-ray、photoelectron spectroscopy(XPS),and UV-vis diffuse reflectance spectroscopy(DRS).Under visible-light irradiation,the AgCl/ZnO/GO composites showed excellent photocatalytic activity for effictive removal of methylene orange(MO).Some of operational parameters such as AgCl content,pH,and photocatalyst dosage were investigated.The appropriate molar ratio of AgCI to ZnO was 2:1.At this ratio,in the presence of 70 mg AgCl/ZnO/GO photocatalyst and under visible-light irradiation for 50 min,the degradation efficiency of MO(10 mg/L) was about 98.93%.The mechanism study elucidated that AgCl and GO could effectively reduce the recombination of electron-hole pairs and prolong the lifetime of the electron-holes pairs,therefore promoting the MO degradation efficiency.This study also demonstrated that the composite is a recyclable agent.Its MO removal capacity remained effective(88%) even after four cycles of batch tests.In conclusion,AgCl/ZnO/GO is a highly efficient and stable photocatalyst,which shows great potential in the efficient treatment of organic dyes in wastewater.
作者
朱秋蓉
何世颖
赵晓蕾
唐婉莹
宋小宝
薛利红
杨林章
ZHU Qiurong;HE Shiying;ZHAO Xiaolei;TANG Wanying;SONG Xiaobao;XUE Lihong;YANG Linzhang(School Chemical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China;Institute of Agricultural Science and Environment,Jiangsu Academy of Agricultural Sciences,Nanjing 210014,China)
出处
《环境科学研究》
EI
CAS
CSCD
北大核心
2020年第4期969-977,共9页
Research of Environmental Sciences
基金
国家自然科学基金项目(No.41771295)
国家水体污染控制与治理科技重大专项(No.2017ZX07202004-003)
江苏省六大人才高峰项目(No.NY-054)。
