Mixed reactant photocatalysis: Intermediates and mutual rate inhibition

Turchi, Craig

doi:10.1016/0021-9517(89)90176-0

Cited by 274 publications

(132 citation statements)

References 27 publications

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“…Turchi and Ollis [22] examined this discrepancy and consequently developed the other workers [24][25][26]. Further work on the influence of light on K will be necessary to further elucidate the photocatalytic process.…”

Section: Methodsmentioning

confidence: 99%

The destruction of 2-methylisoborneol and geosmin using titanium dioxide photocatalysis

Lawton

Robertson

et al. 2003

Applied Catalysis B: Environmental

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Geosmin (GSM) and 2-methylisoborneol (MIB) are semi-volatile compounds produced by cyanobacteria in surface waters. These compounds present problems to the drinking water industry and in aquaculture because they can taint water and fish producing an earthy-musty flavour. This paper presents an initial study on the use of TiO 2 photocatalysis for the destruction of these compounds in water. The process proved effective with the complete destruction of MIB and GSM being achieved within 60 minutes. These results suggest that TiO 2 photocatalysis will be a successful method for removal of taint compounds from potable water supplies and fish farms.

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Section: Methodsmentioning

confidence: 99%

The destruction of 2-methylisoborneol and geosmin using titanium dioxide photocatalysis

Lawton

Robertson

et al. 2003

Applied Catalysis B: Environmental

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“…It has been suggested [14] that the adsorption of organic molecules on the catalyst surface is generally an important step in determining photocatalytic degradation rates, and the LangmuirHinshelwood model has been used to describe the kinetics of adsorption-photodegradation reactions [25,26]:…”

Section: Effects Of Adsorption Modes On the Photocatalytic Degradatiomentioning

confidence: 99%

Photocatalytic degradation pathways and adsorption modes of H-acid in TiO2 suspensions

2012

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Effect of adsorption mode on photodegradation of H-acid in TiO 2 suspension was studied using DFT calculation, UV-Vis spectroscopy, FTIR, and ionic chromatography. At pH 2.5, H-acid was adsorbed on TiO 2 surfaces by one dissociated sulfonic group. The adsorbed sulfonic group was attacked by surface ·OH, resulting in the production of SO 4 2− and the cleavage of the naphthalene ring. At pH 5.0, H-acid was adsorbed on TiO 2 surfaces by two sulfonic groups. The two adsorbed sulfonic groups were simultaneously attacked by surface ·OH, leading to a faster initial production of SO 4 2− and initial degradation rate of H-acid than those under pH 2.5. Microscopic adsorption structures may be more important than adsorption amount in controlling the photodegradation pathways of organic pollutants. The heterogeneous photocatalytic degradation of organic compounds on TiO 2 surfaces has been extensively investigated with a view to mineralizing environmentally harmful organic compounds. The adsorption of organic molecules is critical in determining photocatalytic degradation pathways; these pathways are directly related to the equilibrium and kinetic properties of photocatalytic degradation reactions. The process is initiated through band-to-band excitation of the TiO 2 particles by ultraviolet (UV) radiation to generate free ·OH radicals derived from valence band hole oxidation of terminal OH − groups and hydration water on the particle surfaces. These radicals have been assumed to be the dominant oxidizing agents, with a preference for attacking organic compounds adsorbed on or near the TiO 2 surfaces for quick quenching [1]. Since surface adsorption is required for interactions between the organic molecules and the photo-excited electrons or holes, differences in adsorption modes should affect photocatalytic degradation pathways. Many authors have investigated the adsorption of organic compounds on TiO 2 surfaces [2−6]. However, few studies have correlated adsorption mechanisms in aqueous solutions with degradation behavior occurring under the same conditions. Recently, a metastable-equilibrium adsorption (MEA) theory has been developed by Pan et al. [7,8], which points out that the adsorption density  (mol/m 2 ) has been incorrectly used in the past as a thermodynamic state variable in the theoretical foundations of classical surface thermodynamics. Once this deficiency is removed from classical surface thermodynamics, a new principle, called MEA inequality, is obtained, based on strict theoretical deductions from first principles. The MEA inequality indicates that real "equilibrium" adsorption constants decrease as the actual MEA states deviate from the ideal equilibrium state. Equilibrium adsorption constants or adsorption isotherms, when expressed in terms of , are fundamentally influenced by kinetic factors such as reaction rate and the reversibility of the adsorption process [9−12]. This implies that the equilibrium constants of heterogeneous catalytic reactions can be fundamentally influenced by MEA states. This wo...

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“…Smart antimicrobial coatings may also be used to coat medical implants that are suspected to cause infection, tissue destruction, premature device failure or the spread of infection to other areas (58)(59)(60)(61).…”

Section: Figure 3 Schematic Representation Of Switching Behavior Ofmentioning

confidence: 99%

“…Subsequently, antibiotic drugs are released which were originally used as actual monomers in the synthesis of the polymer itself. Since the inflammatory response is activated in the presence of bacteria or injury, which may predispose a patient to infection (58), an antibiotic could be released, proportionate to the magnitude of the response. Since polyester-urethanes have been shown to be susceptible to degradation by inflammatory enzymes (63), a polymer containing similar chemistry is targeted as an initial model for this investigation.…”

Section: Figure 3 Schematic Representation Of Switching Behavior Ofmentioning

confidence: 99%

Smart Coatings

Baghdachi

2009

ACS Symposium Series

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Materials that are capable of adapting their properties dynamically to an external stimulus are called responsive, or smart. The term "smart coating" refers to the concept of coatings being able to sense their environment and make an appropriate response to that stimulus. The standard thinking regarding coatings has been as a passive layer unresponsive to the environment. The current trend in coatings technology is to control the coating composition on a molecular level and the morphology at the nanometer scale. The idea of controlling the assembly of sequential macromolecular layers and the development that materials can form defined structures with unique properties is being explored for both pure scientific research and industrial applications. Several smart coating systems have been developed, examined, and are currently under investigation by numerous laboratories and industries throughout the world. Examples of smart coatings include stimuli responsive, antimicrobial, antifouling, conductive, self-healing, and super hydrophobic systems.

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Mixed reactant photocatalysis: Intermediates and mutual rate inhibition

Cited by 274 publications

References 27 publications

The destruction of 2-methylisoborneol and geosmin using titanium dioxide photocatalysis

The destruction of 2-methylisoborneol and geosmin using titanium dioxide photocatalysis

Photocatalytic degradation pathways and adsorption modes of H-acid in TiO2 suspensions

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