Gong Wen-qi

Preparation of TiO2/Kaolinite Nanocomposite and Its Photocatalytical Activity

Titanium dioxide/kaolinite nanocomposite was prepared by the sol-gel method, with layered kaolinite as a substrate and Ti(OC4H9)4 as a precursor. The effects of hydrolysis, drying and calcination on the production of nanometric titanium dioxide were discussed. The optimal conditions for preparation were obtained through experiments. The 1–10 nm thick monolayer anatase nano TiO2 crystal was produced under the conditions as follows: hydrolyzed at 37–42 °C for 4 h, dried at 70–80 °C for 1 h, and calcined at 550–650 °C for 3 h. The rate of degradation of 40 mg/L azo dye and 20 mg/L acid red dye can reach 96% and 81.45%, respectively.

Preparation, Characterization and Visible Light Photocatalytic Activity of Nitrogen-doped TiO2

The N-doped TiO2 polycrystalline powder was synthesized through calcining the hydrolysis product of tetra-butyl titanate with ammonia. The photocatalytic activity of N-doped TiO2 powder with anatase phase calcined at 400 °C was 2.7 times higher than that of Degussa P25 for phenol decomposition under visible light. All samples had mesoporous structures. X-ray photoelectron spectroscopy confirmed that a trace amount of N atoms remained in the anatase polycrystalline TiO2 powder when calcined at 400 °C as substitutional atoms at the oxygen sites. UV-Vis and EPR analyses indicated that oxygen vacancy states were created during the course of N-doped TiO2 powder formation. It is considered that substitutional N atoms, oxygen vacancy states, large BET surface areas and mesoporous structure are important factors for the N-doped photocatalyst to present a high vis-activity.

Preparation of Intercalated Clay/Phenolic Resin Nanocomposites under High Pressure

High pressure method was used for the first time to produce rectorite clay (REC)/phenolic resin (PF) and organic rectorite clay (OREC)/phenolic resin and montmorillonite (MMT)/phenolic resin (PF) nanocomposites. The structure of the material phase was studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), and atomic force microscopy (AFM). The experimental results show that intercalated clay/resin nanocomposites could form under normal temperature and high pressure conditions by the intercalation of polymeric molecules rather than interlayer polymerization.