Fabrication of Hollow Silica Nanorods Using Nanocrystalline Cellulose as Templates

A simple approach to fabricate hollow silica nanorods is reported, using nanocrystalline cellulose (NCC) as templates. Uniform NCC with the length of ca. 100 nm and a diameter of ca. 10 nm were prepared by hydrolysis of microcrystalline cellulose (MCC) in strong sulfuric acid condition. NCC was used as a template to prepare a core-shell composite of silica and NCC. The sol-gel reaction of tetraethyl orthosilicate (TEOS) was employed to coat NCC with a nano thickness of silica in the presence of ammonia. Finally, hollow silica nanorods were obtained by calcination of the composite at 600°C to remove the organic cellulose template completely. The obtained hollow silica nanorods were found to have uniform size and shape: with a length of ca. 100 nm, an inner diameter close to the original diameter of NCC, and a thickness of around 10 to 15 nm. These results suggest that NCC is an excellent template for manufacturing nano hollow materials with uniform shape and size.