QUICK-SCANNING EXAFS IN THE REFLECTION MODE AS A PROBE FOR STRUCTURALINFORMATION OF ELECTRODE SURFACES WITH TIME RESOLUTION - AN IN-SITU STUDY OF ANODIC SILVER-OXIDE FORMATION

Time-dependent extended X-ray absorption fine structure (QEXAFS) measu rements using the total external reflection geometry were used for the in situ investigation of the potentiostatic silver oxide formation in 1 M NaOH. It is demonstrated that this EXAFS tool yielding near range order structural information is well suited for time-resolved studies of electrode surfaces under potential control. As examples, the initi al growth stages of thin silver(I) oxide layers are presented as well as changes of the near range order of thick Ag2O films induced by pote ntiostatic transients. A comparison of the experimental results with t hose of model calculations permits the determination of the reaction k inetics of electrochemical phase formation.