Wenjun Yao

An enhanced CdS/TiO2 photocatalyst with high stability and activity: Effect of mesoporous substrate and bifunctional linking molecule

To accomplish the more effective coupling of cadmium sulfide quantum dots (CdS QDs), the mesoporous TiO2 substrate and bifunctional linker, mercaptopropionic acid (MPA), were used to disperse and stabilize the CdS QDs. Due to the porous nano-architecture on the TiO2 substrate with large surface area and high crystallinity, the efficiency of degradation of organic compounds in aqueous solution under visible light irradiation is greatly enhanced, compared to CdS loaded anatase TiO2 without porous structure and common commercial P25. Furthermore, the bifunctional linking molecule, MPA, could effectively disperse and stabilize CdS nanoparticles. CdS/TiO2 with the linking molecule CdS-MPA-TiO2(m) exhibits much more stability and activity than CdS-TiO2(m) which is prepared by direct deposition. After 3 cycling tests of degradation of MB (methylene blue), the loss ratio of CdS on CdS-TiO2(m) is 70.6%, much larger than that of 17.8% on CdS-MPA-TiO2(m). This work may give ideas for the synthesis of other stable and active supported catalysts in many fields.

Synthesis, Features, and Applications of Mesoporous Titania with TiO2(B)

The mesoporous titania with TiO2(B) (mt-TiO2(B)), which has a lattice-matched core-shell crystalline structure with a thin TiO2(B) phase sheathing an anatase core, was synthesized from potassium titanate (K2Ti2O5) by hydration, ion exchange, and calcination. TiO2(B) is a crystalline form of titania with a looser structure than anatase and rutile. Its synthesis, structure, and functions are reviewed. It has all the features of a large specific surface area with a mesoporous architecture, pore wall of high crystallinity and high thermostability. Nanoparticles of noble metals in this mesoporous structured titania are stable. Its potential industrial applications include photocatalysis, oil hydrorefining, and use as a drug carrier, solid acid catalyst, and electrode material. A pilot plant to prepare this unique multifunctional titania material at low cost has been established with a production capacity of 20 tons per year.