Research Of Long-life Ag/AgX Reference Electrode Material

In the ocean, there are many metal materials on ship, offshore platforms,and so on. Corrosion monitoring of the metal material is the most important in safety monitoring. In cathodic protector system for subsea metal structures, measuring electrical chemistry parameters is needed. It is necessary to have a reference electrode that is accuratet and stable. At present, the Ag/AgCl reference electrode is in common use in sea water.Because of the complicated composition of sea water, the stability of the Ag/AgCl reference electrode is influenced by the existence of ion, such as Br^-, SO4^2-,which lead to short life.In this paper, in order to solve the problems of the Ag/AgCl electrode, a Ag/AgX reference electrode was prepared by thermal-dip coating method. It showed that the stability and anti-polarization ability was better when the AgCl/AgBr was 77/23. And the R and R_p of the electrode were smaller at this ratio. There would be enough AgX on the silver matrix and good performance oe the electrode when the fusible temperature was 500℃.The effect of the parameters of reduction was studied. E of the electrode moved to negative direction along with the extension of the time of H₂ reduction(t1).The stability of E was bad when t1 is small.Along with the extension of t₁,R and R_p became smaller, while the proportion became lager.There was no obvious effect of density of the reductive current (I) on E.When I getting stronger, R and R_p became smaller, while the proportion became larger. E moved to negative direction along with the extension of the electrochemistry reductive time (t2).The stability of E was bad when t is small.Along with the extension of t₂,R and R_p became smaller first, and then larger.On the contrary, the proportion of the electrode became larger first, and then smaller.The was no effect of reductive method on E. But R and R_p of the electrode prepared by electrochemistry reductive method were smaller. And the anti-polarization ability was much better. The electrochemistry performances of the Ag/AgX reference electrode were tested. The temperature coefficient of the electrode was 0.31mV/℃.The reversible ability of the electrode was good. E moved to negative direction with rhe increases of the density of Br^-.