Effects of Particle Size of TiO2 on Photocatalytic Degradation of Methylene Blue in Aqueous Suspensions

✍ Scribed by Xu, Nanping; Shi, Zaifeng; Fan, Yiqun; Dong, Junhang; Shi, Jun; Hu, Michael Z.-C.

• Book ID: 111683431
• Publisher: American Chemical Society
• Year: 1999
• Tongue: English
• Weight: 124 KB
• Volume: 38
• Category: Article
• ISSN: 0888-5885
• DOI: 10.1021/ie980378u

✦ Synopsis

The influence of particle size of TiO 2 on the photocatalytic degradation of methylene blue (MB) in a suspended aqueous solution has been studied. The results suggested that the adsorption rate and adsorbability of MB on suspended TiO 2 particles increased as the particle sizes of TiO 2 decreased. Photocatalytic activity of TiO 2 also increased as the particle size of TiO 2 became smaller, especially when the particle size is less than 30 nm. The half-life (t 0.5 ) of the photocatalytic degradation of MB also decreased as the particle sizes of TiO 2 decreased. The first-order reaction rate constant for photodegradation of MB increased as the particle size of TiO 2 decreased. The initial degradation rate of MB in a suspended model was higher than that of a fixed-bed model. This will overcome the difficulty of preparation of ultrafine TiO 2 catalyst particles. Once the problem of separation of fine TiO 2 particles is solved, a TiO 2 suspended photoreactor could be provided on an industrial basis.