Synthesis of mesoporous composite materials of nitrogen-doped carbon and silica using a reactive surfactant approach

Abstract

Mesoporous composite materials of nitrogen-doped carbon and silica were synthesised in a one-step-process applying a soft templating procedure. The template used in the sol–gel synthesis of the silica is a cationic surfactant with distinct reactivity to form nitrogen-doped graphitic carbon upon heating. This reactivity is derived from the combination of the dicyanamide anion with a nitrogen-containing pyridinium cation, as it is known from ionic liquids used as nitrogen-doped carbon precursors. Thus applying this surfactant in a conventional sol–gel synthesis yields a silica gel doped with a precursor for N-doped carbon. By subsequent annealing mesoporous composite materials of silica and nitrogen-doped carbon are obtained.