(81c) Fabrication of Nanoporous Silicon Oxycarbide Materials Using Layered Double Hydroxide As a Sacrificial Template

Nanoporous silicon oxycarbide is considered to be a promising material for a variety of applications. Highly porous silicon oxycarbide materials with high surface area and a hierarchical pore size distribution were successfully synthesized using tri-isopropylsilane (TPS) as a precursor and a layered double-hydroxide (LDH) as a sacrificial template via chemical vapor deposition (CVD) at the relatively low temperatures of 700 ^oC – 800 ^oC. Techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission and scanning electron microscopies (TEM or SEM) were used to characterize the resulting materials and showed them to be hollow spheres with layered structures. Nitrogen adsorption-desorption (BET) measurements also validate the fact that the synthesized porous Si_xO_yC_z materials have hierarchical structures containing both mesopores and micropores. The materials exhibit high BET surface areas ranging from 360 m²/g to 540 m²/g and total pore volumes from 0.69 cm³/g to 0.91cm³/g. The Si_xO_yC_z materials fabricated in this research, using low cost templates and precursors and convenient synthesis procedures, have desirable structural properties, and show promise for applications as catalysis support, sorbents, battery anodes, and membrane films for water filtration and gas separations applications.