纳米结构金电极上对氨基苯硫酚的电化学反应过程研究  

Investigation on Electrochemical Processes of p-Aminothiophenol on Gold Electrode of Nanostructures

作　　者：彭辉远 王家正 刘佳 于欢欢 林建德 吴德印[1] 田中群[1] Hui-Yuan Peng;Jia-Zheng Wang;Jia Liu;Huan-Huan Yu;Jian-De Lin;De-Yin Wu;Zhong-Qun Tian(State Key Laboratory of Physical Chemistry of Solid Surfaces,Department of Chemistry,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,Fujian,China)

机构地区：[1]厦门大学化学化工学院,固体表面物理化学国家重点实验室,福建厦门361005

出　　处：《电化学》2022年第4期1-8,共8页Journal of Electrochemistry

基　　金：国家自然科学基金项目(No.22032004,No.21533066,No.21773197)资助。

摘　　要：本文研究了金电极上吸附对氨基苯硫酚(PATP)的电化学行为。在0.05 mol·L^(-1)的硫酸溶液(pH=1)中,从循环伏安图中可观察到PATP的不可逆电氧化峰。基于吸附PATP电化学氧化为4′-巯基-N-苯基醌二亚胺(NPQD)的反应机理,计算了电极表面PATP的覆盖度,并在低激光功率下通过电化学表面增强拉曼光谱进行了氧化产物表征。通过电化学线性扫描伏安法及理论模拟计算,确定了PATP电化学氧化的动力学参数,即表观反应速率常数k及传递系数α,确定了生成阳离子自由基的步骤为速率控制步骤。Electrochemical reactions on nanostructured noble electrodes have received much attention,however,the reaction mechanism and reaction kinetics are still difficult to be studied.Probe molecule can give an insight to the investigation of electrochemical reactions on noble electrodes with nanostructures.In this paper,the electrochemical process of p-aminothiophenol(PATP)adsorbed on the gold electrode was studied by electrochemical cyclic voltammetry and surface-enhanced Raman spectroscopy(SERS).Here,we used one-step sodium citrate reduction method(Frens method)to synthesize gold nanoparticles,which are used to construct the nanostructured gold electrode.The Raman electrolytic cell used was based on the traditional three-electrode electrolytic cell.The gold electrode was used as the working electrode(WE),the saturated calomel electrode(SCE)as the reference electrode(RE),and the platinum wire(Pt)as the counter electrode(CE).After the careful pretreatment of the gold electrode surface,the cell was assembled and placed on the platform of the XploRa instrument to get started.With the assistance of potentiostat,the SERS spectra at different potentials were acquired and combined together,a so-call electrochemical surface-enhanced Raman spectroscopic(EC-SERS)experiment.In a 0.05 mol·L^(-1) sulfuric acid solution(pH=1),an irreversible oxidation peak was found in the cyclic voltammogram,which is considered to correspond to the oxidation of the PATP molecule.The oxidation mechanism is proposed by combination of previous work in literature,and it is pointed out that the PATP molecule was initially transformed into cationic radical.Then,this cationic radical coupled with the PATP molecule to an intermediate NPQDH2,and finally electrochemically oxidized to 4'-mercapto-N-phenylquinone diamine(NPQD).On the basis of this mechanism,the surface coverage of PATP on the electrode surface was calculated and the coverage value was found to be larger at the nanostructured electrode due to the modification of gold nanoparticles than that o

关 键 词：对氨基苯硫酚 覆盖度 电化学表面增强拉曼光谱 线性扫描伏安法 理论模拟 

分 类 号：O657.37[理学—分析化学] TB383.1[理学—化学]