Electrochemical Investigation Of Current Oscillatory Phenomena At The Liquid/liquid Interface

Liquid/liquid interface，as a simple simulation model, has got rapidly developmentin the past few decades and application in many fields such as the extraction process,electrochemical sensing, phase transfer catalysis, drug delivery and biomimeticmembranes. This paper briefly reviewed the development history of liquid/liquidinterface electrochemistry，and introduced the progress of the current oscillatoryphenomenon at the liquid/liquid interface. Meanwhile, the current oscillatoryphenomena at the liquid/liquid interface were also investigated by the cyclicvoltammetry and chronoamperometry, combining DFT theory calculation and specificadsorption of ion pair model.This article includes four chapters, and the main content are as follows:1. In this chapter, we summarized the progress of the liquid/liquid interfaceelectrochemistry, introduced the liquid/liquid interface model and research methods.In addition, the characteristics of the surfactant were also discussed.2. The current oscillatory phenomenon based on Cu²⁺was systematicallyinvestigated at the Water/1,2-dichloroethane （W/DCE） interface by cyclicvoltammetry and chronoamperometry. It was found that the oscillation phenomenaonly occurred near the oxidation peak of CuCl₂-, and were related to Cu²⁺concentrations in the aqueous phase. The mechanism of oscillation at the W/DCEinterface were also investigated with theoretical calculation combined a specificadsorption of ion pair model. It is significant for us to understand the structure of theliquid/liquid interface and to explore liquid/liquid interface oscillation mechanism.3. The oscillatory phenomenon based on Fe³⁺/Fe²⁺was systematically studied at theW/DCE interface by cyclic voltammetric technique. The results demonstrate that thecurrent oscillation only occurred in the site of oxidation peak of Fe²⁺, and was relatedto the concentrations of both Fe³⁺ in the aqueous phase and TPB-in the organic phase,which indicates that the oscillation feature is the specific adsorption of ion pairforming mechanism in W/DCE interface. In addition, the mechanism of oscillation atthe W/DCE interface were also studied by the theoretical calculation combined a specific adsorption of ion pair model.4. The influence of surfactants(C₁₈H₂₉NaO₃S and Triton X-100) on the currentoscillation phenomena was studied in both Fe（CN）₆^3-/Fe（CN）₆^4- and Fe³⁺/Fe²⁺atW/DCE interface. The experiment result suggested that the oscillatory phenomenonwill disappear when the concentrations of the surfactant are larger than their CMC.