Tingshun Jiang

Preparation of mesoporous titania solid superacid and its catalytic property

Mesoporous titania (TiO(2)) was synthesized by hydrothermal method using cetyltrimethyl ammonium bromide (CTAB) as a template and using anhydrous ethanol and tetra-n-butyl titanate (TBOT) as raw materials. Mesoporous titania solid superacid and nanosized titania solid superacid catalysts were prepared by wet impregnation method. The structure and property of as-prepared samples were characterized by means of XRD, FT-IR and N(2) physical adsorption. The esterification of salicylic acid with isoamyl alcohol and the condensation of cyclohexanone with ethylene were used as model reactions to test the catalytic activities of the catalysts. On the other hand, the comparison of catalytic activities of the prepared solid superacid catalysts and the conventional liquid acid H(2)SO(4) was also carried out under the same experimental conditions. The results show that the catalytic activities of the prepared solid superacid catalysts were higher than that of the conventional liquid acid H(2)SO(4), and that the catalytic activity of mesoporous TiO(2) solid superacid is the highest among the three catalysts. Mesoporous TiO(2) solid superacid is a good catalyst for the synthesis of isoamyl salicylate or cyclohexanone ethylene ketal.

A facile synthesis of graphene–metal (Pb, Zn, Cd, Mn) sulfide composites

We propose a general approach for the preparation of graphene-metal sulfide quantum dots (QDs) composites by π–π stacking of pyridine-capped metal sulfide QDs and chemically converted graphene (CCG) in aqueous solution. CCG sheets disperse stably in water without the assistance of dispersing agents, only by electrostatic repulsion. The aromatic structures of pyridine capped on metal sulfide QDs make these QDs dispersible in ethanol or water, and further introduce a π–π stacking interaction between CCG and QDs, and extend the conjugated structure of CCG. The structural details, formation mechanism, and textural properties of the resultant graphene-metal sulfide QDs composites are characterized by X-ray diffraction, UV–vis absorption, electron microscopy, and Raman scattering studies. The CCG–metal sulfide composites disperse stably in aqueous solution, allowing them to be potentially used in biological tissues and easy-to-form filtered films for further research and application.

Synthesis and characterization of Ni-mesoporous molecular sieves with high stability

Saponites with Ni were hydrothermally synthesized at a given pH using inorganic salts as raw materials. Then, mesoporous molecular sieves with Ni were synthesized hydrothermally using the synthesized saponites as precursors and cetyltrimethyl ammonium bromide as a template. The prepared mesoporous molecular sieves with Ni still had mesoporous structure after calcination at 850°C for 3 h or hydrothermal treatment at 100°C for 10 days.

Characterization of Zr-based MCM-41 mesoporous molecular sieves obtained by microwave irradiation or hydrothermal method

Zr-based MCM-41 mesoporous molecular sieves (ZrMCM-41) were successfully synthesized by microwave irradiation method and hydrothermal method, respectively. The obtained samples were characterized by XRD, TEM, FT-IR and N2 physical adsorption. The results show that the samples synthesized by the two different methods both possess typical hexagonal mesoporous structure of MCM-41 and high specific surface areas (over 800 m2/g). After calcination at 750°C for 3 h or hydrothermal treatment at 100°C for 6 days, the mesoporous structure of the samples still retained, however, the mesoporous ordering is poor. Under the comparable conditions, the reaction time required in the synthesis of ZrMCM-41 by microwave irradiation method was greatly reduced, and microwave irradiation method is eco-friendly and is easy to operate.