title: Kinetic study and modeling on photocatalytic degradation of para-chlorobenzoate at different light intensities.
abstract: In order to clarify the dependence of apparent adsorption constant Ks in the Langmuir-Hinshelwood (L-H) model on the incident light intensity, photocatalytic degradation kinetic characteristics were experimentally investigated at different light intensities using para-chlorobenzoate (4-CBA) as a model compound. In all cases 4-CBA initial degradation rates showed dependence on 4-CBA initial concentration, which can be described by the L-H model. However, the adsorption constant Ks and rate constant kr obviously varied with light intensity. To account for the experimental finding, slight modification of the classic kinetic model developed by Turchi and Ollis was tentatively proposed by assuming insufficiency of H2O/OH- available for photo-activated holes' scavenging. Such a kinetic model predicts that both k(r) and Ks(-1) are linearly proportional to the square root of the intensity in a rather large intensity range. The validity of the modified model was proved by fitting it to the experimental data.
authors.affiliation: Environment Simulation and Pollution Control State Key Joint Laboratory, Department of Environmental Science and Engineering, Tsinghua University, Beijing, People's Republic of China.
authors.forename: Yaobin
authors.initials: Y
authors.lastname: Meng
authors.forename: Xia
authors.initials: X
authors.lastname: Huang
authors.forename: Yingxi
authors.initials: Y
authors.lastname: Wu
authors.forename: Xiaomao
authors.initials: X
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: Qian
mesh_terms: D000327:Adsorption; D002384:Catalysis; D002723:Chlorobenzoates / Q000737:chemistry*; D007700:Kinetics; D008027:Light; D010777:Photochemistry
chemical_list: D002723:Chlorobenzoates; C040768:4-chlorobenzoic acid