Structural arrangement, electroconductivical and electrochemical behaviours of solid amino acid-based electrodes

Abstract

This paper presents the study on the structural dependence of the electroconductivity and electrochemical activity of model amino acids, aspartate, and glycine, which are used as solid electrodes in hybrid capacitor systems. It has been established that the presence of carbonyl, aliphatic, and amide functional groups on the surface ensures electrochemical activity and the manifestation of electrically conductive properties. The frequency dependence of conductivity is typical for polymer compounds with a proton conduction mechanism, which is provided by the surface migration of the charge. It was found that deposition on the surface of carbon templates the amino acids in the formation of biocomposites increases the number of active reaction centers and provides effective electronic charge transport. As a result, it leads to a significant increase in the contribution of pseudocapacitance and capacitance processes. The electrochemical activity was caused by the pseudo-capacitive accumulation of charge due to the course of redox reactions with amino acids and capacitive accumulation of charge, which occurs with the participation of amino acids and carbon templates. It has been proven that the porous structure of the carbon nanotubes provides a more dispersed and uniform distribution of amino acids on the surface, which is ensured in the growth of pseudocapacitive charge accumulation.