Xiaoxing Fan

Photocatalytic Degradation of Acetaldehyde on Mesoporous TiO2: Effects of Surface Area and Crystallinity on the Photocatalytic Activity

Mesoporous TiO2 powder and films with worm-like channels were synthesized by an evaporation-induced self-assembly approach. The as-prepared samples were calcined at different temperature to investigate the effect of calcined temperature on the mesostructure and the photocatalytic activity. Acetaldehyde photodegradation in gas phase was employed to evaluate the photocatalytic activity of mesoporous TiO2. Results showed that all the calcined powder samples exhibited higher photocatalytic activities than that of Degussa P25. The sample calcined at 400C, which showed higher activity than other samples, possessed a homogeneous pore diameter of about 6.0 nm and an 11.0 nm crystalline anatase pore wall, as well as large surface area of 117 m2/g. It was speculated that two factors of surface area and crystallinity affected the photocatalytic activity of mesoporous TiO2 photocatalyst. The mesoporous TiO2 films fabricated by spin-coating also had high photocatalytic activities.

Effect of crystal growth on mesoporous Pb3Nb4O13 formation, and their photocatalytic activity under visible-light irradiation

Visible-light-active mesoporous Pb3Nb4O13 photocatalysts with large specific surface area were synthesized by using the evaporation-induced self-assembly (EISA) approach. We studied the crystal growth properties that influence the formation of mesoporous structures. For some materials with high nucleation density a mesoporous structure with large specific surface area is attainable by using a sol–gel method with a traditional surfactant approach. The photocatalytic activities of the obtained samples were investigated by photo-oxidizing 2-propanol gas. Compared with a Pb3Nb4O13 sample prepared by solid-state reaction, mesoporous Pb3Nb4O13 samples showed greatly improved photocatalytic activity under visible light irradiation (λ > 420 nm).

Preparation of Mesostructured Lamellar Zirconia

Mesostructured lamellar zirconia was synthesized in the hydrothermal systems using Cetyltrimethyl Ammonium Bromide (CTAB) as a template and zirconyl chloride as zirconium precursor. The as-prepared composites were characterized by X-ray diffraction (XRD), TG-DTA, and DR-UV techniques. The influences of hydrothermal aging time, total concentration of solution, different mole ratio of zirconyl chloride/surfactant, and post treatment on the structure of mesostructured lamellar zirconia were discussed in this article.

Photocatalytic H2 or O2 Evolution over A-Site Deficient Perovskite-Type Compounds La1/3MO3 (M = Nb, Ta) from Aqueous Solutions

Two compounds La1/3MO3 (M = Nb, Ta) with A-site deficient perovskite-type structure were synthesized by the solid state reaction method. The photocatalytic properties of these compounds were characterized by H2 evolution with Pt cocatalyst from CH3OH/H2O solution and by O2 evolution from AgNO3 aqueous solution under UV light irradiation. The results showed that the average rate of H2 evolution was about 61.07 μmol h-1 for La1/3NbO3 and 95.79 μmol h-1 for La1/3TaO3 after 24 hours of reaction time, while the initial rate of O2 evolution was 26.31 μmol h-1 for La1/3NbO3 and 16.21 μmol h-1 for La1/3TaO3, respectively. H2 evolution was also observed over La1/3MO3 (M = Nb, Ta) with NiO cocatalyst from pure water under UV light irradiation.

Hybrid mesoporous SC/SBA as a chemosensor for recognizing Cu2+

A novel organic/inorganic hybrid material was synthesized involving the self-assembly of fluorescent molecules (4-chloroaniline-N-salicylidene, SC) within the channel of modified SBA-15. The fluorescent active hybrid mesoporous material exhibits high selectivity for sensing Cu 2+ in polar solution.