Highly active and thermo-stable anatase TiO2 photocatalysts synthesized by a microwave-assisted hydrothermal method

Microwave-assisted hydrothermal (MAH) route is simple and scalable for phase-pure A-TiO2 preparation. The photocatalytic activity of TiO2 nanoparticles has been confirmed through the photocatalytic de-colorization of methylene blue under simulated sunlight. The photocatalytic activity is enhanced with an increase of annealing temperature. The phase-pure A-TiO2 annealed at 800 °C exhibits a much higher de-colorization rate than the commercially available TiO2 (Degussa P25) powders. The much higher photocatalytic activity of this sample is due to its enhanced crystallinity, leading to a lower rate of electron/hole pair recombination and a larger photocurrent density in comparison to all other samples and P25. The sample annealed at 900 °C shows the highest intrinsic photocatalytic activity, demonstrating the importance of thermal stability and crystalline phase.