Fabrication and Characterization of Mesostructured Silica, HUM-1, and Its Ordered Mesoporous Carbon Replica

The consecutive replications initiated with MCM-48 silica were carried out to synthesize ordered mesostructures of carbon and silica as evidenced by powder X-ray diffraction and transmission electron microscopy. However, ordered mesoporous carbon obtained via replication of the MCM-48 silica exhibited different structural symmetry than that of MCM-48, and its replication afforded a new silica mesostructure, HUM-1. The subsequent nanocasting of HUM-1 led to a new second-generation carbon replica. The pore size analysis performed on the basis of nitrogen adsorption isotherms indicates that the HUM-1 silica possesses larger mesopores in comparison to those present in the initial MCM-48 silica, which is probably due to the structural change occurring during the first replication of MCM-48. The pore size distributions are similar for both mesoporous carbons and show bimodal shape.