Microemulsion-Mediated Room-Temperature Synthesis of High-Surface-Area Rutile and Its Photocatalytic Performance

Abstract

Nanosized titania having the rutile crystalline structure was synthesized at room temperature using a microemulsion-mediated system. The formed rutile particles had a diameter of 3 nm, which corresponds well with the droplet size of the water-in-oil microemulsion used for their preparation. The crystallinity was monitored by both X-ray diffraction (XRD) and electron diffraction, together with dark-field electron microscopy (TEM) and high-resolution TEM. The rutile had a high specific surface area (∼300 m2/g) according to N2 adsorption and the BET equation. To our knowledge, this is the highest specific surface area ever reported for rutile. The rutile crystals aligned in a specific crystallographic direction forming elongated aggregates 200−1000 nm in size, as observed by TEM and high-resolution TEM. The titania formation was followed in situ using dynamic light scattering and UV−vis spectroscopy, and together with TEM and XRD performed on samples collected throughout the duration of the titania synthesis...