Journal article
Kinetic Study of 4-nitrophenol Photocatalytic Degradation over a Zn2+ Doped TiO2 Catalyst prepared through an Environmentally Friendly Aqueous Sol-Gel Process
Chemical Engineering Journal, Vol.245, pp.180-190
2014
Abstract
A kinetic study of the photocatalytic degradation of 4-nitrophenol (4-NP) under UV-Visible light (330 nm less than λ less than 800 nm) has been performed via a rigorous chemical engineering approach over a Zn2+ doped TiO2 catalyst prepared through an environmentally friendly aqueous sol-gel process. The experiments have been performed at three temperatures to enable the global activation energy to be estimated. The influence of the illumination intensity has also been considered. The possibility of internal and external diffusion limitations has been studied and the results obtained demonstrated that there is no diffusional limitation during the photocatalytic degradation of the 4-NP using the selected catalyst. Therefore, the apparent specific reaction rate measured corresponds to the actual reaction rate of the chemical reaction. Parameter adjustments show that the kinetic model that provides the best fit to the experimental data corresponds to a first order reaction. A sequence of elementary steps has been considered and a pseudo-steady state approach based upon the stationary state hypothesis for reaction intermediates has been applied to obtain a kinetic rate expression in agreement with the experimental data. The mean values of the reaction rate constant found at 283 K, 288 K and 293 K are respectively equal to k1‾ = 0.094±0.003 m3 h-1 kgcatalyst-1; k2‾ = 0.119±0.004 m3 h-1 kgcatalyst-1 and k3‾ = 0.150±0.023 m3 h-1 kgcatalyst-1 and the global activation energy of the degradation reaction was evaluated as 40 kJ mol-1. A phenomenological kinetic mechanism is proposed to describe the reaction at a molecular scale. Finally, statistical validations and residuals analysis have been performed to confirm that the first order model is suitable to represent the 4-NP photocatalytic degradation over time. Such studies are essential to design a reactor for water pollutant degradation on an industrial scale.
Details
- Title
- Kinetic Study of 4-nitrophenol Photocatalytic Degradation over a Zn2+ Doped TiO2 Catalyst prepared through an Environmentally Friendly Aqueous Sol-Gel Process
- Authors
- Charline M Malengreaux (Author) - Universite de Liege, BelgiumSophie L Pirard (Author) - Universite de Liege, BelgiumJohn R Bartlett (Author) - University of the Sunshine Coast - Faculty of Science, Health, Education and EngineeringBenoit Heinrichs (Author) - Universite de Liege, Belgium
- Publication details
- Chemical Engineering Journal, Vol.245, pp.180-190
- Publisher
- Elsevier BV
- Date published
- 2014
- DOI
- 10.1016/j.cej.2014.01.068
- ISSN
- 1385-8947
- Copyright note
- Copyright © 2014. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
- Organisation Unit
- School of Science and Engineering - Legacy; University of the Sunshine Coast, Queensland
- Language
- English
- Record Identifier
- 99449963702621
- Output Type
- Journal article
Metrics
515 File views/ downloads
1544 Record Views
InCites Highlights
These are selected metrics from InCites Benchmarking & Analytics tool, related to this output
- Collaboration types
- Domestic collaboration
- International collaboration
- Web Of Science research areas
- Engineering, Chemical
- Engineering, Environmental