Physicochemical characterization of ordered mesoporous carbons functionalized by wet oxidation

Ordered mesoporous carbon obtained by the soft template method was subjected to oxidation with the use of ammonium persulfate or nitric acid. The material was modified in different conditions in order to generate on its surface oxygen functional groups. Functionalization of carbon with nitric acid or ammonium persulfate at low temperatures caused a reduction in its surface area and pore volume. At elevated temperatures, the oxidation with (NH₄)₂S₂O₈ solution brought about an increase in these parameters, which is related, among others, with increased area of micropores. Transmission electron microscopy images confirm that the application of ammonium persulfate as an oxidizer does not lead to structural changes in carbon. FT-IR spectra and Boehm titration results proved that irrespective of the oxidation conditions, the process leads to generation of oxygen functional groups. Their highest content was observed for the carbon sample oxidized by a 5 M solution of HNO₃ at 100 °C.