原位SERS研究Au纳米结构表面SPR催化对硝基碘苯偶联反应  

In-Situ SERS Monitoring of SPR-Catalyzed Coupling Reaction of p-Nitroiodobenzene on Noble Metal Nanoparticles

作　　者：魏玉兰 张晨杰[1] 袁亚仙[1] 姚建林[1] WEI Yu-lan;ZHANG Chen-jie;YUAN Ya-xian;YAO Jian-lin(College of Chemistry,Chemical Engineering and Materials Science,Soochow University,Suzhou 215123,China)

机构地区：[1]苏州大学材料与化学化工学部,江苏苏州215123

出　　处：《光谱学与光谱分析》2024年第9期2482-2487,共6页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(22172109,21773166)资助。

摘　　要：表面增强拉曼光谱(SERS)因其极高灵敏度和表面特异性,可用于表面等离激元共振(SPR)催化反应过程的原位监测。利用SERS技术原位研究对硝基碘苯(PNIB)在贵金属纳米粒子表面的催化偶联反应过程。研究了激光功率、波长及基底对催化偶联的影响,初步研究了该偶联反应的机理。研究表明,PNIB在金纳米粒子单层膜(Au MLF)表面发生SPR催化偶联反应生成1,2-双(4-碘苯基)二氮烯,增大激光功率可使反应达到平衡时间明显缩短。Au@Ag纳米膜表面偶联效率提高了约10倍,不同基底表面的偶联反应活性为Au@Ag(532nm)>Au@Ag(638nm)>Au(638nm)。该反应为热电子诱导的还原反应。Surface-enhanced Raman spectroscopy(SERS)derived from surface plasmon resonance(SPR)has become an effective tool for surface analysis because of its high sensitivity and surface specificity.Moreover,SPR can induce and stimulate the catalytic reaction on the surface of noble metal nanostructures.The combination of SERS and SPR is beneficial to in-situ monitoring of SPR catalytic reaction at the surface interface of noble metals.This paper used p-nitroiodobenzene(PNIB)as a probe molecule to demonstrate SERS's capability in characterizing catalytic coupling reactions.The effects of laser power,wavelength,and substrate on the catalytic coupling were investigated,and the mechanism of the coupling reaction was proposed preliminary.The results revealed that azo compound 1,2-bis(4-iodophenyl)diazene was produced by SPR-catalyzed coupling reaction of PNIB on the surface of gold nanoparticle monolayer film(Au MLF).The equilibrium of the reaction was reached with short duration by increasing laser power,i.e.,from 200sat 3mW to about 50sat 15mW.The coupling efficiency was increased to about doubled.On the Au@Ag nanoparticle film,the coupling efficiency is increased by about 10times,and the coupling efficiency is significantly dependent on the excitation wavelength and SERS substrates.The reaction activity order of different substrate surfaces is Au@Ag(532nm)>Au@Ag(638nm)>Au(638nm).It demonstrated that the hole-trapping agent sodium sulfite increase the coupling efficiency of the reaction by about an order of magnitude.It indicated that the reaction of PNIB coupling to 1,2-bis(4-iodophenyl)diazene catalyzed by SPR is a reduction reaction induced by hot electrons.

关 键 词：表面增强拉曼光谱 对硝基碘苯 表面等离激元共振催化 偶联反应 贵金属纳米粒子 

分 类 号：O657.3[理学—分析化学]