摘要
以硝酸镨、硝酸铁、柠檬酸为主要原料,提纯后的凹凸棒石(ATP)作为载体,采用溶胶−凝胶−浸渍法制备碳量子点(CQDs)修饰PrFeO3/ATP复合材料。采用X射线衍射(XRD)、透射电子显微镜(TEM)、紫外可见漫反射谱(UV-Vis DRS)及傅里叶变换红外光谱(FT-IR)等对复合材料的形貌结构进行表征,考察不同CQDs负载量对复合材料光催化氧化脱硝性能的影响。结果表明:CQDs的引入显著提高了复合材料的脱硝性能,当CQDs负载量为4%(质量分数)时,CQDs/PrFeO3/ATP复合材料对NO的光氧化活性最高,转化率达到85%。提出可能的机理在于:PrFeO3受到可见光的照射激发产生的电子从价带跃迁至导带,光生电子迅速迁移到CQDs上并产生超氧自由基,空穴仍然留在PrFeO3的价带,二者具有强氧化性将NO氧化成NO3-。CQDs的引入促进了光生电子与空穴的分离,同时扩展了复合材料的光谱吸收范围,凹凸棒石表面的微孔结构也有利于NO气体的吸附增加其与活性组分的接触,这种协同效应使得复合材料的光催化脱硝性能得到提高。
By CQDs-(Carbon quantum dots)modified PrFeO3/attapulgite(ATP)composites were prepared by sol-gel/impregnation method using ATP as support,Pr(NO3)3,Fe(NO3)3 and citric acid as raw materials.The morphology and structure of the composites were characterized by X-ray diffractometer(XRD),transmission electron microscope(TEM),UV-Vis diffuse reflectance spectroscope(UV-Vis DRS)and Fourier transform infrared spectroscope(FT-IR).The photocatalytic denitrification was investigated with different mass ratios of CQDs.The results show that the incorporation of CQDs remarkably promotes the photocatalytic activity of the composite.When the loading amount of the carbon quantum dots is 4%(mass fraction),the NO conversion rate of the composite reaches the highest of 85%.The mechanism is put forward as follows,under visible light irradiation,the PrFeO3 is excited where the electrons jump from the valence band to the conductive band,and the electrons quickly migrate to the CQDs forming super oxygen radicals,while the holes remain in the valence band of PrFeO3,both of them had super oxidation property and further oxidized NO to NO3^-.The CQDs not only facilitate the separation of photogene rated electrons and holes,but also extend the spectrum absorption range of the composites.Such synergistic effect is expected to improve the photocatalytic denitration performance of the products.
作者
何承溧
李霞章
周永生
左士祥
罗士平
姚超
HE Cheng-li;LI Xia-zhang;ZHOU Yong-sheng;ZUO Shi-xiang;LUO Shi-ping;YAO Chao(Advanced Catalytic and Green Manufacturing Collaborative Innovation Center,Changzhou University,Changzhou 213164,China)
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2020年第11期2627-2633,共7页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(51674043,51702026)。
关键词
稀土钙钛矿
凹凸棒石
碳量子点
光氧化脱硝
rare earth perovskite
attapulgite
carbon quantum dots
photocatalytic oxidation denitration
作者简介
通信作者:李霞章,副研究员,博士,电话:0519-86330027,E-mail:xiazhang@cczu.edu.cn;姚超,教授,博士,电话:0519-86330027,E-mail:yaochao@cczu.edu.cn。
