Researchers at Sharif University of Technology, Iran, managed to synthesize TiO2 nanoparticles with high specific surface area and high activity by using ionic solvent through gel cell method. These nanoparticles are capable of destroying Blue 92 Acid photocatalytically.
"Heterogeneous photocatalysts in which TiO2 is coupled are given great attention in advanced oxidation processes," Shanaz Ghasemi, one of the researchers, said to the news service of INIC.
Hydrolysis and condensation reactions are happening very fast in the solutions used in gel cell method for synthesis of TiO2 nanoparticles. It leads to uncontrollable physical and chemical properties of produced nanoparticles.
In some ways network structure of TiO2 is not stable enough to prevent Ti-O-Ti bonds from breaking during phase conversion of anatase to rutile under thermal treatment, in other ways thermal treatment at high temperatures is necessary for phase conversion and Ti-O-Ti bond breakage is inevitable in these conversions.
Therefore, the synthesis of TiO2 nanoparticles with high specific surface area, high activity, and in low temperature thermal treatments seems essential. For this purpose, gel cell processes are done in ionic solvents.
In this study, the researchers first synthesized TiO2 nanoparticles by gel cell method using 2-hydroxy ethyl ammonium formate. Then, they examined temperature increase and transient metals effects on surface morphology and TiO2 nanoparticles photocatalytic activity.
The effects of different parameters such as color concentration, photocatalyst amount, solution pH, and concentration of oxidant materials like H2O2 on the rate and efficiency of color destruction were also studied.
You can find more details at Journal of Hazardous Materials, volume 172, pages 1573 to 1578, 2009.