Atomic Layer Deposition for the Conformal Coating of Nanoporous Materials

Abstract

Atomic layer deposition (ALD) is ideal for applying precise and conformal coatings over nanoporous materials. We have recently usedALDto coat two nanoporous solids: anodic aluminum oxide (AAO) and silica aerogels.AAOpossesses hexagonally ordered pores with diametersd∼40nm and pore lengthL∼70microns. TheAAOmembranes were coated byALDto fabricate catalytic membranes that demonstrate remarkable selectivity in the oxidative dehydrogenation of cyclohexane. AdditionalAAOmembranes coated withALDPd films show promise as hydrogen sensors. Silica aerogels have the lowest density and highest surface area of any solid material. Consequently, these materials serve as an excellent substrate to fabricate novel catalytic materials and gas sensors byALD.