Structure of the Electrical Double Layer Revisited: Electrode Capacitance in Aqueous Solutions

• DOI: 10.1021/acs.langmuir.0c00024
• Publication Date: 2020-03-31T18:33:01Z
• Authors: Mahmoud Khademi; Dominik P. J. Barz
• Keywords: Differential capacitance; Double layer (biology)

The structure of the electrical double layer at interface planar electrodes and aqueous solutions is investigated. Electrical impedance spectroscopy used to measure sodium chloride two different surfactants over a wide range concentrations. electrode capacitance directly inferred from admittance spectra as well by regression an equivalent circuit. It found that remains on same order magnitude entire investigated This contradictive predictions Gouy-Chapman-Stern theory which predicts that, low concentrations, should be determined diffuse layer. concluded Stern always dominates capacitance, even very establishment requires ionic strength around 1 mM.