STUDY OF ELECTROCHEMICAL INTERCALATION OF GRAPHITE IN SOLUTIONS OF HNO3 WITH METHOD OF CHRONOVOLTAMPEROMETRY

Abstract

For citation:Yakovlev A.V., Finaenov A.I., Yakovleva E.V., Kuznetsova N.Yu., Abdullina D.F. Study of electrochemical intercalation of graphite in solutions of HNO3 with method of chronovoltamperometry. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 1. P. 34-39.The physico-chemical properties of suspensions of graphite-nitric acid were studied. The ratios of the components in suspension providing the possibility of their anodic oxidation with the formation of compounds of the implementation of graphite were determined. The values of electrical conductivity of suspensions of graphite-nitric acid with different ratio of the solid and liquid phases were determined .The maximum value of the electrical conductivity of suspensions is achieved at the mass ratio of graphite to HNO3» 1:0.66. The design of the electrochemical cell for carrying out chronovoltamperometric measurements on a suspension graphite electrode was developed. The nature and kinetics of electrode processes on dispersed graphite electrodes in 60% nitric acid were studied. It is shown that under anodic polarization of dispersion graphite electrode the complex of anodic processes occurs: the oxidation of surface of functional groups, the formation of compounds of implementation and evolution of oxygen. Maximum electrochemical reversibility of the anodic processes on the suspensions of graphite-HNO3 observed at Erev< 1.2 V, the rate of reactions of formation of compounds of the introduction of graphite and reactions involving surface functional groups on the electrode slurry increases in the range of potentials of 1.2-1.7 V. At that, the current is increase mainly causes by electrochemically reversible process of intercalation, since at the reverse cycle in the cathode area also recorded the growth of the current due to the reaction of deintercalation. An electrochemical oxidation of dispersed graphite electrode in HNO3 should be in the range of potentials from 1.2 V to 2.1 V, which will provide formation of compounds of introduction of graphite with the maximum rate and minimum power input.