In this project, it will be studied the current and potential oscillations that occur during the electro-oxidation of the sulfur-containing compounds on gold electrodes. Sulfur is an element that shows many different oxidation states and some chemical instabilities phenomena can be observed. The interpretation of these phenomena on kinetics instabilities during the electro-oxidation of some sulfur-containing compounds, such as Na2S and thiourea on platinum electrodes, have showed that such systems could oscillate under galvanostatic and potentiostatic control. On the other hand, given the known strong interaction between sulfur atoms and gold surfaces, cf. self-assembled monolayers of alkanethiols, it is astonishing the absence of studies on the kinetics instabilities related to the electro-oxidation of sulfur-containing compounds on gold. In this way, the present project aims to study the electro-oxidation of sulfur-containing compounds (as thiocyanate) on gold surfaces, looking for a better understanding on the mechanism related to the kinetic instabilities. The study will be carried out by means of classic electrochemical techniques, electrochemical quartz crystal nanobalance and UV-Vis in situ. Based on preliminary experiments, it has been observed rich dynamics related to the system sulfur-gold electrode, mainly when those observed are compared to the electro-oxidation of small organic molecules on platinum electrodes. Therefore, it is believed that the development of the project will be able to open interesting perspectives in the complex chemical kinetic field on the electrified solid-liquid interface.
News published in Agência FAPESP Newsletter about the scholarship: