An in situ diffuse reflectance FTIR investigation of photocatalytic degradation of 4-chlorophenol on a TiO2 powder surface

✍ Scribed by Ulick Stafford; Kimberly A. Gray; Prashnat V. Kamat; Arvind Varma

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 662 KB
• Volume: 205
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(93)85166-l

✦ Synopsis

An in situ FTIR technique has been employed to probe the adsorption and photocatalytic degradation of 4<hlorophenol (4-CP) on TiOz particles in a gas/solid system. The chemisorbed 4-CP adsorbed on the Ti02 surface corresponds to a monolayer. The reaction has been followed under a number of conditions in order to investigate the roles of oxygen and water in the mechanism of 4-CP degradation. The rate of 4-CP disappearance was greatest under an oxygen atmosphere saturated with water and with UV irradiation. Under these conditions hydroquinone (HQ) was observed as a primary reaction intermediate and carboa ates as the final product. Transformation of 4-CP to HQ was seen to occur under a variety of reaction conditions (i.e. 0,/W, N2/H20/UV), but HQ degradation took place only in the presence of oxygen and UV irradiation. These results illustrate that the interactions of 4-CP at the semiconductor surface are complex and suggest that oxygen is intrinsically involved in the degradation