Modification to L-H Kinetics Model and Its Application in the Investigation on Photodegradation of Gaseous Benzene by Nitrogen-Doped TiO2

In this paper, the Langmuir-Hinshelwood (L-H) model has been used to investigate the kinetics of photodegradation of gaseous benzene by nitrogen-doped TiO2 (N-TiO2) at 25 °C under visible light irradiation. Experimental results show that the photoreaction coefficient kpm increased from 3.992 × 10−6 mol·kg−1·s−1 to 11.55 × 10−6 mol·kg−1·s−1 along with increasing illumination intensity. However, the adsorption equilibrium constant KL decreased from 1139 to 597 m3·mol−1 when the illumination intensity increased from 36.7 × 104 lx to 75.1 × 104 lx, whereas it was 2761 m3·mol−1 in the absence of light. This is contrary to the fact that KL should be a constant if the temperature was fixed. This phenomenon can be attributed to the breaking of the adsorption-desorption equilibrium by photocatalytically decomposition. To compensate for the disequilibrium of the adsorption-desorption process, photoreaction coefficient kpm was introduced to the expression of KL and the compensation form was denoted as Km. KL is an indicator of the adsorption capacity of TiO2 while Km is only an indicator of the coverage ratio of TiO2 surface. The modified L-H model has been experimentally verified so it is expected to be used to predict the kinetics of the photocatalytic degradation of gaseous benzene.

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Chemical diffusion analysis of the oxidation kinetics of oxygen-deficient, nitrogen doped TiO2 thin films

Solid State Ionics ◽

10.1016/j.ssi.2019.115044 ◽

2019 ◽

Vol 341 ◽

pp. 115044

Author(s):

Misha Sinder ◽

Jianmin Shi ◽

Klaus-Dieter Becker

Keyword(s):

Thin Films ◽

Oxidation Kinetics ◽

Chemical Diffusion ◽

Tio2 Thin Films ◽

Doped Tio2 ◽

Nitrogen Doped ◽

Diffusion Analysis ◽

Kinetics Of

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Kinetics of Nitrogen Doped TiO2 for Degradation of Rhodamine B

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.183-185.2037 ◽

2011 ◽

Vol 183-185 ◽

pp. 2037-2040

Author(s):

Sheng Min Sun ◽

Qian Nie

Keyword(s):

Rhodamine B ◽

Ph Value ◽

Urea Solution ◽

Tetrabutyl Titanate ◽

Ultrasonic Dispersion ◽

Doped Tio2 ◽

Nitrogen Doped ◽

Degradation Ratio ◽

Effects Of Ph ◽

Kinetics Of

Nitrogen doped TiO2 Photocatalysts was prepared by ultrasonic dispersion method based on the predominated materials as tetrabutyl titanate with the dopant of saturated Urea solution. The dynamic behavior of nitrogen doped TiO2 for the degradation of rhodamine B was researched on the catalyst volume and the effects of pH value on photocatalysis ratio. Results showed that the catalytic reaction was accord with the first class reaction dynamic model. When the catalyst was 0.1g and the pH value close to 7, the degradation ratio was the maximum.

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Oxidation kinetics of nitrogen doped TiO2−δ thin films

Physical Chemistry Chemical Physics ◽

10.1039/c2cp42559a ◽

2012 ◽

Vol 14 (37) ◽

pp. 12930 ◽

Cited By ~ 9

Author(s):

Jianmin Shi ◽

Doh-Kwon Lee ◽

Han-Ill Yoo ◽

Jürgen Janek ◽

Klaus-Dieter Becker

Keyword(s):

Thin Films ◽

Oxidation Kinetics ◽

Doped Tio2 ◽

Nitrogen Doped ◽

Kinetics Of

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Desorption rate of glyphosate from goethite as affected by different entering ligands: hints on the desorption mechanism

Environmental Chemistry ◽

10.1071/en17004 ◽

2017 ◽

Vol 14 (5) ◽

pp. 288 ◽

Cited By ~ 3

Author(s):

Jeison M. Arroyave ◽

Carolina C. Waiman ◽

Graciela P. Zanini ◽

Wenfeng Tan ◽

Marcelo J. Avena

Keyword(s):

Desorption Kinetics ◽

Desorption Rate ◽

Mineral Surfaces ◽

Desorption Process ◽

Ligand Exchange Reaction ◽

Mineral Particles ◽

Desorption Rate Constant ◽

Desorption Mechanism ◽

Adsorption Desorption ◽

Kinetics Of

Environmental contextGlyphosate is a heavily used herbicide that is mobilised in soil and sediments through adsorption–desorption processes from the surface of mineral particles. We demonstrate that the desorption rate of glyphosate from goethite, a ubiquitous mineral, is nearly independent of the concentration and nature of the substance that is used to desorb it. The results elucidate the desorption mechanism and are relevant to understand and predict the environmental mobility of glyphosate. AbstractThe desorption kinetics of glyphosate (Gly) from goethite was studied in a flow cell using attenuated total reflectance Fourier-transform infrared spectroscopy. Because Gly forms an inner-sphere surface complex by coordinating to Fe atoms at the goethite surface, the desorption process is actually a ligand-exchange reaction, where Gly is the leaving ligand and water molecules or dissolved substances are the entering ligands. A series of possible entering ligands that can be found in nature was tested to evaluate their effect on the desorption kinetics of Gly. Contrarily to expectations, the desorption rate was quite independent of the entering ligand concentration. Moreover, the identity of this ligand (phosphate, citrate, sulfate, oxalate, EDTA, thiocyanate, humic acid, water) had only a small effect on the value of the desorption rate constant. By analogy with the reactivity of transition metal complexes in solution, it is concluded that the rate is mainly controlled by the breaking of the Fe–Gly bond, through a dissociative or a dissociative interchange mechanism. The results are relevant in understanding and predicting the environmental mobility of Gly: irrespective of the identity of the entering ligand, Gly will always desorb from iron (hydr)oxides in nature at nearly the same rate, simplifying calculations and predictions enormously. The importance of studying desorption kinetics using mineral surfaces and environmentally relevant molecules is also highlighted.

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