Nano-sized TiO₂ Synthesis in Triton X-100 Reverse Micelles

Abstract

To synthesize nano-sized TiO₂, two different methods, namely thermal hydrolysis (TH) and reverse micelles as the nano reactors in the thermal hydrolysis method (RM-TH) were used, and their effects on the shape, crystal structure, and size of the TiO₂ particles produced were investigated. In the RM-TH method, reverse micelles prepared by Triton X-100 / Cyclohexane / Aqueous TiCl₄ solution was used as a template since the hydrolysis reaction took place in the aqueous core of the reverse micelle that led to a controllable synthesis of TiO₂ particles. The XRD patterns of the as-prepared TiO₂ particles produced by both methods indicated that their crystal structure was rutile. In the TH method, particles were highly agglomerated resulting in a pinecone-like structure: The pinecone-like structure contained several rods with a diameter of 50 nm which were formed by conical bundles of fine rods growing radially from the center with a diameter of 6 nm and length ranged between 400 and 1000 nm. On the other hand, more uniform sphere-like nanoclusters consisting of radially growing nanorods from the center with a diameter of 6 nm and length of 200 nm were produced in the RM-TH method due to the template feature of reverse micelles. Mechanisms of nucleation and crystal growth were proposed for both production methods.