Singlet Oxygen Production upon Two-Photon Excitation of TiO2 in Chloroform

✍ Scribed by Wenbing Li; Naveen Gandra; Shavelle N. Courtney; Ruomei Gao

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 474 KB
• Volume: 10
• Category: Article
• ISSN: 1439-4235
• DOI: 10.1002/cphc.200900155

✦ Synopsis

Abstract

Singlet oxygen (^1^O~2~) signals observed upon illumination at 532 nm are a consequence of TiO~2~ excitation in a two‐photon process, and at 355 nm in a one‐photon pathway. After corrections for light reflectance, the relative quantum yields of ^1^O~2~ production are 0.23±0.01 and 0.22±0.02 for 532 and 355 nm excitation, respectively. Total quenching rate constants of ^1^O~2~ removal by TiO~2~ particles are near the diffusion‐controlled rate limit. By employing ^1^O~2~ as a probe, we have established an efficient and simple method to elucidate the nature of TiO~2~ photoexcitation.