Synthesis of Nanostructured Titania Templated by Anionic Surfactant in Acidic Conditions

Nanostructured titania was synthesized by hydrolysis of titanium tetraisopropoxide (TTIP) in HCl acidic conditions using sodium dodecylsulfate (SDS) as the templating agent. The resultant SDS-titania composite solids were supposed to possess the lamellar nanostructure, which collapsed by calcination. The order of the nanostructure was improved with increasing the SDS/TTIP molar ratio. The nanostructure order also increased with the HCl/TTIP molar ratios, probably due to the enhanced attraction between the positively charged surfaces of titania clusters and the head groups of anionic surfactant. The calcined sample presented an advanced mesopore structure with uniform pore size and the surface area of ca. 200 m²/g, although the periodicity of the nanostructure was exceedingly reduced by the removal of the template. It is supposed that the mesopore structure did not result from the templated nanostructure, but was derived from the spaces between titania nano-sized particles closely arranged by the attraction with SDS molecular assemblies.