Hydrothermal Synthesis of Highly Water-dispersible Anatase Nanoparticles with Large Specific Surface Area and Their Adsorptive Properties

Highly water-dispersible and very small TiO2 nanoparticles (similar to 3 nm anatase) with large specific surface area have been synthesized by hydrolysis and hydrothermal reactions of titanium butoxide and used for the removal of three azo dyes (Congo red, orange II, and methyl orange) with different molecular structure from simulated wastewaters. The synthesized TiO2 nanoparticles are well dispersed in water with large specific surface area up to 417 m(2) g(-1). Adsorption experiments demonstrated that the water-dispersible TiO2 nanoparticles possess excellent adsorption capacities for Congo red, orange II, and methyl orange, which could be attributed to their good water-dispersibility and large specific surface area.