Preparation, Characterization, and Surface Modification of Periodic Mesoporous Silicon–Aluminum–Carbon–Nitrogen Frameworks

Abstract

Periodic mesoporous silicon–aluminum–carbon–nitrogen (Si/Al/C/N) frameworks with P6mm hexagonal symmetry were synthesized by a solvent nanocasting route using mesoporous carbon (CMK-3) as hard template and preceramic polymers containing both −[R1R2Si–N(R3)]n– and −[R4Al–N(R5)]n– backbones (with R1 = R2 = R3 = R4 = H and R5 = CH2CH3) as ceramic precursors. The preceramic polymers are prepared through a simple and cost-effective procedure by blending poly(perhydropolysilazane) and poly(ethyliminoalane) as precursors of silicon nitride/silicon (Si3N4/Si) and carbon-containing aluminum nitride (Al/C/N), respectively. The blended polymers with various and controlled Al:Si ratios were infiltrated into the porous structure of CMK-3, followed by a pyrolysis-template removal cycle performed under nitrogen at 1000 °C (2 h, ceramic conversion), then in an ammonia atmosphere at 1000 °C (5 h, template removal). This procedure resulted in the formation of periodic mesoporous Si/Al/C/N frameworks with surface areas of 1...