Synthesis,characterization,and activity of a covalently anchored heterogeneous perylene diimide photocatalyst  

异相光催化剂苝酰亚胺的合成、表征及活性(英文)

作　　者：Jinting Shang Hanying Tang Hongwei Ji Wanhong Ma Chuncheng Chen Jincai Zhao 商锦婷;唐瀚滢;籍宏伟;马万红;陈春城;赵进才(中国科学院化学研究所光化学院重点实验室,北京100190;中国科学院大学,北京100049)

机构地区：[1]Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China [2]University of Chinese Academy of Sciences, Beijing 100049, China

出　　处：《Chinese Journal of Catalysis》2017年第12期2094-2101,共8页催化学报（英文）

基　　金：supported by the National Natural Science Foundation of China(21525729,21590811,21521062,2177168);the "Strategic Priority Research Program" of the Chinese Academy of Sciences(XDA09030200);the "CAS Interdisciplinary Innovation Team Program"~~

摘　　要：The consecutive two‐photon photocatalytic behavior of perylene diimide(PDI)enables it to catalyze photoreduction reactions that are thermodynamically unfavorable via single‐photon processes.In this work,we developed a heterogeneous PDI photocatalyst by covalently binding PDI molecules on the surface of nanosilica.This photocatalyst structure overcomes the intrinsic limitation of the low solubility of PDI,but retains its consecutive two‐photon photocatalytic property.Detailed characterization of the photocatalyst by techniques such as thermogravimetric analysis,solid‐state nuclear magnetic resonance spectroscopy,and Fourier transform infrared spectroscopy indicated that the PDI molecules were anchored covalently on the surface of nanosilica.The obtained photocatalyst reduced aryl halides under visible‐light irradiation in polar organic solvent and in water.The present study provides a promising strategy to realize two‐photon activity of PDI in common solvents for photocatalytic applications.光催化是催化反应中非常重要的一个领域,其中可见光催化反应在实际应用中尤为重要.近几十年,众多研究者致力于可见光催化剂的研究,如有机染料、有机金属复合物和共价有机聚合物等都是常见的可见光催化剂.近年来,人们发现苝酰亚胺(PDI)是一类活性非常高的可见光催化剂,因为一个PDI分子可以连续吸收两个光子而积累足够的能量,使得许多单光子过程能量不足以激发的反应能够顺利进行.然而,由于PDI结构中存在大共轭的苯环,其在大部分溶剂中的溶解度都比较低,尤其是在水相中很难溶解,因此限制了它的应用.本文将PDI分子通过共价键键合在纳米二氧化硅表面,合成了一种新的多相PDI光催化剂(SN-PDI),解决了PDI在很多溶剂中都难以分散的问题,同时保留了它双光子吸收的光催化特性.我们首先合成了表面修饰有氨基的纳米二氧化硅,然后与苝酐反应,从而将PDI键合在二氧化硅表面.利用二氧化硅的亲水性使得PDI在水中以及大部分溶剂中很好地分散和分离,从而充分发挥PDI的光催化还原性能.通过^(29)Si固体核磁(NMR)、X射线光电子能谱(XPS)、^(13)C固体核磁、傅里叶变换红外光谱(FT-IR)、紫外-可见吸收光谱以及热重分析等手段表征了合成后的SN-PDI.其中^(29)Si固体核磁谱图中化学位移在-66 ppm处的峰证明了缩合形成的纳米二氧化硅中带有氨基,根据峰面积得到其中33%的硅原子上连有氨基.XPS结果发现,N 1s轨道有明显位移,说明合成后N原子的化学环境发生了明显变化.^(13)C NMR结果表明,合成前后与氨基相连的几个碳也发生了较大位移,与理论一致.FT-IR发现苝酐中酸酐特征峰消失以及亚胺特征峰出现,证明PDI成功键合在了二氧化硅表面.以十溴联苯醚和4-溴苯乙酮作为卤代底物,分别在有机相和水相中采用SN-PDI光催化降解反应,结果均得到了脱卤后的产物.催化剂循环三次�

关 键 词：Visible light PHOTOCATALYSIS NANOSILICA Perylene diimide DEBROMINATION 

分 类 号：O643.36[理学—物理化学] O644.1[理学—化学]