RESUMO
To summarize: The works presented in this and the previous paper (2) have produced an operational model for describing the oxygen reduction process in common medical grade sterile saline media at a platinum disc shaped electrode with a fairly specific surface conditioning. This paper has illustrated some of the variations possible in electrode current responses. An important feature of these data is that they are highly consistent and repeatable and can be discussed in terms of the model. However, the question still remains: What is the aging process? Is it due to a decrease of active sites for the electrochemical reduction process, brought about by the reduction process itself, or is it a process caused by other species in the media? To answer these questions, it may be necessary to employ some of the sophisticated techniques such as angle-resolved photoelectron spectroscopy (4) and extended x-ray absorption fine structure (5), available today for the study of atomic and molecular arrangements on solid surfaces.