Photocatalytic degradation of formaldehyde using mesoporous TiO_2 prepared by evaporation-induced self-assembly

The mesoporous Ti O2 has been synthesized by evaporation induced self assembly(EISA) method. The thermogravimetric/differential scanning calorimetric(TG/DSC), X-ray diffraction(XRD), high-resolution transmission electron microscopy(HR-TEM) and N2 adsorption desorption and adsorption are used to study the effects of the synthesized process condition on the microstructure of the as-synthesized mesoporous Ti O2. The photocatalytic performances of as-synthesized samples are evaluated by the degradation of the formaldehyde under ultraviolet light irradiations. The results demonstrate that the as-synthesized mesoporous Ti O2 are anatase with the uniform size about 20-40 nm. The sample is prepared using cetyltrimethyl ammonium bromide(CTAB) as the template with average pore size distribution of 8.12 nm, specific surface area of 68.47 m2/g and pore volume of 0.213 m L/g. The samples show decomposition of formaldehyde 95.8% under ultraviolet light irradiations for 90 min. These results provide a basic experimental process for preparation mesoporous Ti O2, which will posses a broad prospect in terms of the applications in improving indoor air quality.

Template preparation of twisted nanoparticles of mesoporous silica

Optical isomers of N-lauroyl-L-（Or-D-） alanine sodium salt {C12-L-（Or-D-）AIaS} surfactants were used for the preparation of mesoporous silica nanoparticles with a twisted hexagonal rod-like morphology. Thermogravimetric analysis （TGA） was used to determine the temperature for template removal. Circular dichroism （CD） spectra of the surfactant solution with various compositions illustrated the formation and supramolecular assembly of protein-like molecular architecture leading to formation of twisted nanopar- ticles. Scanning electron microscopy （SEM）, high-resolution transmission electron microscopy （HRTEM） and X-ray powder diffraction （XRD） patterns of these as-synthesized mesoporous silica confirmed that the twisted morphology of these nanoparticles was closely related to the supramolecular-assembled complex of amino acid surfactants.