BaTiO₃ nanoparticles and nanorods synthesized in carbon nanohorns

Abstract

Porous carbons have the potential to be an ideal template for various materials, because of their simple geometry and various shapes. We synthesized BaTiO₃ nanocrystals in the internal nanopores of carbon nanohorns by sol-gel methods. Direct synthesis of BaTiO₃ in carbon nanohorns produced 2∼4 nm diameter spherical particles, although a typical sol-gel technique for nanoceramic synthesis produces spherical crystals with a diameter of the order of 10 nm. The BaTiO₃ nanoceramics were composed of only a few crystal unit cells, and can be considered zero-dimensional BaTiO₃ nanoceramics. BaTiO₃ nanoceramics synthesized by TiO₂ synthesis in carbon nanohorns and subsequent insertion of barium diethoxide were one-dimensional structures with a high aspect ratio (2∼4 nm in diameter and 40∼60 nm in length). Those nano-spherical and rod-like BaTiO₃ nanoceramics are required in nanotechnology for their unique dielectric and piezoelectric properties.