Gyroidal mesoporous multifunctional nanocomposites via atomic layer deposition

Abstract

We demonstrate the preparation of rationally designed, multifunctional, monolithic and periodically ordered mesoporous core–shell nanocomposites with tunable structural characteristics. Three-dimensionally (3D) co-continuous gyroidal mesoporous polymer monoliths are fabricated from a solution-based triblock terpolymer–resol co-assembly and used as the functional templates for the fabrication of free-standing core–shell carbon–titania composites using atomic layer deposition (ALD). The deposition depth into the torturous gyroidal nanonetwork is investigated as a function of ALD conditions and the resulting composites are submitted to different thermal treatments. Results suggest that ALD can homogenously coat mesoporous templates with well defined pore sizes below 50 nm and thicknesses above 10 μm. Structural tunability like titania shell thickness and pore size control is demonstrated. The ordered nanocomposites exhibit triple functionality; a 3D continuous conductive carbon core that is coated with a crystalline titania shell that in turn is in contact with a 3D continuous mesopore network in a compact monolithic architecture. This materials design is of interest for applications including energy conversion and storage. Gyroidal mesoporous titania monoliths can be obtained through simultaneous titania crystallization and template removal in air.