Abstract
The electrochemical behaviors of polycrystalline silver electrodes in 8M KOH solutions containing $Bi_2O_3$ were studied under various conditions by cyclic voltammetry, potentiostatic and galvanostatic techniques as well as the morphology of the silver oxide structures by SEM. It was found that three new compounds comprising silver, bismuth, and oxygen as well as $Bi_2O_3$, $Ag_2O$ and AgO were formed during the electrochemical oxidation of silver. In addition, the potentiostatic current transients were characterized by the appearances of the first current peaks corresponding to the formation of silver oxides, and the second current peaks corresponding to the Ag-Bi-O compounds, indicating the presence of the nucleation and 3D growth mechanism, in the potential regions of $Ag_2O$ and AgO, respectively. Microscopic examinations showed that two types of silver (I) oxide morphologies are formed in the potential region of $Ag_2O$.
$Bi_2O_3$를 첨가한 8M KOH용액에서 다결정 Ag전극의 전기화학적인 거동과 생성된 산화물들의 미세조직 변화를 분석하였다. $Bi_2O_3$를 첨가한 8M KOH용액에서 Ag 산화물뿐만 아니라 새로운 Ag-Bi-O화합물들이 생성되는 것을 알 수 있었다. Ag(I) 산화물 생성 전위 영역에서는 $Ag_2O$ 이외에, Ag-Bi-O 화합물이 핵 생성과 3D성장 과정에 의해서 생성되고, Ag(II)산화물 생성 전위 영역에서는 AgO뿐만 아니라 새로운 Ag-Bi-O화합물들이 핵 생성과 3D성장 과정에 의해서 생성되었다. Ag(I) 산화물 생성 전위에서 두 가지 형상의 Ag(I) 산화물이 생성되는 것을 SEM 조직에 의해 관찰하였다.