Variable thickness thin-layer cell for electrochemistry and in situ UV–VIS absorption, luminescence and surface-enhanced Raman spectroelectrochemistry

Abstract

A variable thickness thin layer spectroelectrochemical cell for in situ UV–VIS absorption, luminescence and surface-enhanced Raman spectroscopy measurement is described. It is constructed of chemically resistant polytetrafluoroethylene (PTFE) materials. The cell windows, working electrode, reference and auxiliary electrode are all assembled by a mechanical method. The cell is leak-light, easily disassembled and reassembled, and suitable for the study of both aqueous and non-aqueous systems. The thickness of thin layer can be varied from 10 μm to the dimension of a conventional electrochemical cell by adjusting the copper barrel thumbscrew mounted with the working electrode. The working electrode can be easily replaced by another for different experimental conditions. Three working electrodes of Cu, Ag and Au are used for an in situ surface-enhanced Raman spectroelectrochemical study of pyridine. Potassium hexacyanoferrate(III) and ferrocene were used to test the electrochemical performance of the cell under various thin layer conditions (from 10 to 500 μm) in both aqueous and non-queous solutions. Values of E 0′ and n obtained from the in situ UV–VIS absorption and fluorescence spectroelectrochemical study of o-tolidine are 0.608 V (versus SCE) and 1.94 and 0.608 V (versus SCE) and 1.85, respectively. These results agree with the value of 0.605 V (versus SCE) obtained by cyclic voltammetry and values in the literature.