Abstract: Combined with cyclic voltammetry,the Electrochemical Quartz Crystal Microbalance(EQCM) technique was used to study the redox behavior of silver in an alkaline solution.By insitu recording the change of mass in the process of polarization,the dependence of mass on voltage in accordance with the cyclic voltammogram was obtained.Before the formation of the bulk of Ag₂O,a process of competition between the dissolution and the formation of AgOH(or hydrous Ag₂O) surface-layer was detected.Alittle unexpected increase of mass was found at the beginning of the reduction of AgO to Ag₂O,and the exceptional increase was discussed in terms of formation of a surface-compound and the change in the double layer structure.Acomparison was made between the measuring time derivative of the frequency and the calculating value based on current.According to this comparison,we valued the effectivity of EQCM in the study of the process of phase transfermation.

Key words: Quartz crystal microbalance(QCM), Silver electrode, Mass response