Photomineralization of 4-chlorophenol sensitized by titanium dioxide: a study of the initial kinetics of carbon dioxide photogeneration

✍ Scribed by Andrew Mills; Siân Morris

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 840 KB
• Volume: 71
• Category: Article
• ISSN: 1010-6030
• DOI: 10.1016/1010-6030(93)87012-c

✦ Synopsis

The kinetics of photomineralization of 4-chlorophenol (4-CP) sensitized by Degussa P25 TiOt in O+aturated solution is studied as a function of the following different experimental parameters: pH, [TiOJ, percentage O2 [O,], [4-CP], T, 4 A and [IWO,]. At pH 2 and T=30 "C the initial relative rate of CO, photogeneration RCCB conforms to a Langmuir-Hinshelwood-type kinetic scheme and the relationship between R, and the various experimental parameters may be summarized as follows: rKo,O2"K(4-CP)[4-CP], RcoZ= (1 +Ko,[o,])(l +K(4-cP)[4-cP],)

where y is a proportionality constant, K%= 0.044f0.005[02]-', 0-0.74~0.05 and K(CCP)=(29i-3)X l@ dm' mol-'. The overall activation energy for this photosystem was determined as 1622 kJ mol-'. This work forms part of an overall characterization study in which it is proposed that the 4-CP-TiOZ-OZ photosystem is adopted as a standard test system for incorporation into all future semiconductor-sensitized photomineralization studies in order to facilitate comparisons between the results of the different studies.