Chem. J. Chinese Universities ›› 2024, Vol. 45 ›› Issue (1): 20230349.doi: 10.7503/cjcu20230349

• Physical Chemistry • Previous Articles     Next Articles

Electrochemical-SERS Investigation on the Decarboxylated Reaction of PMBA in Ionic Liquid and Influence of Interfacial Water

QIN Haijing, HE Qianjun, XU Minmin, YUAN Yaxian, YAO Jianlin()   

  1. College of Chemistry,Chemical Engineering and Materials Science,Soochow University,Suzhou 215123,China
  • Received:2023-07-29 Online:2024-01-10 Published:2023-10-20
  • Contact: YAO Jianlin E-mail:jlyao@suda.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(22172109);the Key Program of Natural Science Research Project of Jiangsu Colleges and Universities, China(21KJA150009)

Abstract:

Based on the gas-liquid interface self-assembly method and transfer technology, a glassy carbon electrode loaded with Au nanoparticles monolayer(Au MLF@GC) was prepared, and it was employed to in situ study the interfacial processes of ionic liquid electrochemical systems. The decarboxylation of p-mercaptobenzoic acid(PMBA) catalyzed by surface plasmon resonance(SPR) to phenylthiophenol(TP) as the probe reaction, the electrochemical surface-enhanced Raman spectroscopy(SERS) was developed to investigated the kinetic behaviours of the reaction of PMBA in [BMIm]BF4 systems via the potential-step method. The potential of zero charge(pzc) of the hydrophilic ionic liquid [BMIm]BF4/Au MLF@GC was determined to be -0.95 V by the differential capacitance and i-t measurements for electrode immersion. The decarboxylation of PMBA occurred in the positive region of the pzc, and the reaction rate constant was determined based on the second order kinetic reaction and change of the SERS intensities of relevant peaks. The linear relationship between the logarithm of the reaction rate constant and the step potential was resolved. With the addition of extra-water (XW) from 0 to 0.001 and 0.003(molar ratio), the initial step potential was shifted negatively, and the reaction rate constant increased with the addition of water at the same step potential.

Key words: Ionic liquid, Surface-enhanced Raman spectroscopy, Electrochemistry, Decarboxylated reaction rate constant, Potential of zero charge

CLC Number: 

TrendMD: