Exfoliation and Reassembling Route to Mesoporous Titania Nanohybrids

To fabricate mesoporous photocatalysts with delaminated structure, the exfoliated layered titanate in aqueous solution was reassembled in the presence of anatase TiO 2 nanosol particles to induce a great number of mesopores and eventually a large surface area of TiO 2 photocatalysts. No (0 l 0) peaks corresponding to the layered titanate appear in the X-ray diffraction patterns of the reassembled hybrids, which suggests that the titanate nanosheets were randomly hybridized with TiO 2 nanoparticles without any restacking into the layered phase. According to the high-resolution transmission electron microscopy images of these nanohybrids, the randomly oriented titanate nanosheets can be seen clearly along with TiO 2 nanosol particles with spherical images, indicating that the exfoliated sheets are indeed incorporated with anatase nanosol particles to form porous materials. From N 2 adsorption−desorption isotherms, these nanohybrids are fairly high in specific surface area and in mesoporosity for effective photocatalysis ( S BET = ∼190 m 2 /g, pore size = ∼6 nm). The photocatalytic activity of the present mesoporous nanohybrids is superior to that of TiO 2 nanosol particles or layered titanate alone in terms of the degradation of organic pollutants such as 4-chlorophenol, methyl orange, and methylene blue.