Polymer Brush-Grafted Cellulose Nanocrystals for the Synthesis of Porous Carbon-Coated Titania Nanocomposites

Cellulose nanocrystals (CNCs) are a renewable nanomaterials platform. Their characteristic one-dimensional morphology and surface chemistry offer opportunities for the templated synthesis of functional nanorods and nanotubes. Here we report the template-directed fabrication of mesoporous carbon-coated anatase TiO2 nanotubes using polymer brush-grafted CNCs as nanoreactors. The nanoreactors consisted of a CNC core grafted with a poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) shell made by surface-initiated atom transfer radical polymerisation (SI-ATRP). A water-soluble TiO2 precursor, titanium(iv) bis(ammonium lactato)dihydroxide (TALH), was selectively loaded into the nanoreactor shell via ionic interactions. Pyrolysis of the CNC-g-PDMAEMA/TALH hybrids led to the carbonisation of the polymer template, the removal of the CNC core and the crystallisation of the TALH to produce carbon-coated nanocrystalline anatase. The resulting TiO2/C nanotubes retained similar to 50 wt% of TiO2 and similar to 13% wt% of carbon, and exhibited a specific surface area of similar to 111 m(2) g(-1). The simultaneously forming carbon framework suppressed the growth of titania crystallites to <5 nm. We further demonstrate the potential of our TiO2/C nanomaterials to produce titania anode materials for lithium-ion batteries.