Study On The Solid Reference Electrode For Non-aqueous Solutions

In this paper, urea-formaldehyde resin was selected as frame material, potassium chloride was used as the active substance and Ag/AgCl electrode was used as the substrate electrode and a new solid reference electrode was fabricated. The added inert electrolytes can solubled in water and organic solvents, and they can increase the thermodynamic reversibility of the electrode in non-aqueous systems. The dosage, species of inert electrolyte and the conditions of preparation of solid reference electrode were researched.Then the performances of the electrodes in organic solvents of various polar were researched. The research method was that the solid reference electrode was linked to a three-electrode system with a platinum electrode as the counter electrode and gold as the working electrode. The stability and reproducibility of solid reference electrodes were analyzed through measuring FcMeOH in different organic solvents with cyclic voltammetry, and the results showed that:The solid reference electrodes containing inert electrolyte Bu4NPF6 or Et4NClO4 exhibited good stability and reproducibility, and the performance of the solid reference electrode which was added Et4NClO4 was more desirable. The solid reference electrode which used LiClO4 as the inert electrolyte was used to detect FcMeOH in acetonitrile with cyclic voltammetry and the results showed that LiClO4 cannot reduce or eliminate the liquid junction potential, and it cannot used as inert electrolyte of our tests. The solid reference electrode without inert electrolyte was used to determine FcMeOH with cyclic voltammetry in acetonitrile which contain Et4NClO4 and the results showed the instability of electrode potential. It is necessary to add an inert electrolyte which can reduce or even eliminate the liquid junction potential to the reference electrode and the test solution at the same time.The solid reference electrode containing inert electrolyte Et4NClO4 was used to determine FcMeOH with cyclic voltammetry in the mixture of various ratios of acetonitrile and benzene, and the results illustrated that the homemade solid reference electrode can maintain high stability and reproducibility in the solvents of different polarity.Several solid reference electrodes containing Et4NClO4 curing under different pH were characterized by SEM. The material of electrode body exhibited rich holes and uniform pore size when curing under pH=5. Simultaneously, the solid reference electrodesabove were used to determine FcMeOH respectively with cyclic voltammetry and electrochemical impedance and the results showed that the solid reference electrode curing under pH=5 exhibited excellent performance. The BET specific surface area analysis showed the material of solid reference electrode containing mesoporous structure and the performance of the solid reference electrodes was less affected by the specific surface area and the pore size.Several solid reference electrodes containing Et4NClO4 curing under different temperatures were characterized by SEM and electrochemical methods. The material of electrode body exhibited rich holes, uniform pore size and super electrochemical performance when curing under 5 ℃.