Investigations into the Structure of Nitrogen-Containing CMK-3 and OCM-0.75 Carbon Replicas and the Nature of Surface Functional Groups by Spectroscopic and Sorption Techniques

Mesoporous silica matrixes (SBA-15) and multilamellar vesicular (MLV) structures have been used for preparation. of their nitrogen-containing carbon replicas from if pyrrole precursor. The materials have been characterized with microscopic (TEM), spectroscopic (XPS, Raman, E-PR), and sorption techniques. The obtained data show that the resultant CMK-3 and OCM-0.75 replicas exhibit well-developed structures of organized graphene layers, which include surface nitrogen groups located on the graphene sheets and their edges. Influence of the siliceous template loading with FeCl3 on the microstructure of the carbons and speciation of nitrogen has been studied. The built-in nitrogen appears in various surface functional groups that have been identified and quantified with XPS. These groups play a significant role in functionalization of the carbons toward enhanced sorption capacity. The number of paramagnetic defects has been related to the preparation stage of a carbon replica as well as to the chemical status of the heteroatom. A simple model of the surface structure of the materials, based oil the spectroscopic data, has been developed.