The reactivity of phenol in irradiated aqueous suspensions of TiO2. Mechanistic changes as a function of solution pH Article

O'Shea, KE, Cardona, C. (1995). The reactivity of phenol in irradiated aqueous suspensions of TiO2. Mechanistic changes as a function of solution pH . JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY, 91(1), 67-72. 10.1016/1010-6030(95)04103-M

cited authors

  • O'Shea, KE; Cardona, C

authors

abstract

  • The reactivity of phenol under oxic and anoxic conditions in irradiated (350 nm) aqueous suspensions of TiO2 as a function of pH was studied. The initial rate of disappearance of phenol is significantly influenced by solution pH. The initial disappearance rates and Langmuir-Hinshelwood kinetic parameters are comparable over a range from pH 3 to 9 and at pH 13.7, while substantial changes are observed at pH 1 and 11. These differences are attributed to speciation of the reactants and changes in the surface of the TiO2 as a function of solution pH. The involvement of oxide radical anion .O- is proposed at pH ≥ 12. Under highly acidic or basic conditions, colored oligomers are formed as a results, at least in part, of direct photolysis. In the presence of TiO2 the colored oligomers are readily degraded, while in the absence of TiO2 the color continues to develop upon extended irradiation. © 1995.

publication date

  • October 4, 1995

published in

Digital Object Identifier (DOI)

start page

  • 67

end page

  • 72

volume

  • 91

issue

  • 1