Coordination of iron (III) to modified silica surface containing pyrazine acid groups and its application in advanced oxidative processes

Abstract

Within this work, the pyrazine-2,3,5,6-tetracarboxylic acid was attached to the silica surface-treated previously with Ethylene Glycol. Subsequently, the coordination of iron (III) was promoted. The new material was then applied as a catalyst in the heterogeneous Fenton-like degradation of the Methylene Blue molecule model. For such dye, 80% of removal was achieved, proving to be an efficient catalyst. In addition to the experimental discussion, theoretical calculations were carried out to clarify and support steps in the synthetic route. It was presented that the strategy to attach the pyrazine-2,3,5,6-tetracarboxylic acid to a diol modified silica with the subsequent addition of iron results in a new material to be used as a catalyst for the Fenton-like degradation of cationic dyes.