Kinetics and products of the TiO2, photocatalytic degradation of 2-chlorobiphenyl in water

Hong, Chia Swee; Wang, Yongbing; Bush, Brian

doi:10.1016/s0045-6535(97)10040-6

Cited by 79 publications

(34 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is clear that the rate constant is inversely proportional to the initial concentration of pyridine to the lowest limit of 31.74 mg l −1 . The decrease of k obs as increasing the initial pyridine concentration indicates that there is a competition between the instantaneous intermediates and pyridine for the active sites on the catalysts [25]. Considering the results above, the adsorption process can be excluded from the rate-determining step; hence the surface reaction is probably the rate-determining step.…”

Section: Kinetics On the Destruction Of Pyridinementioning

confidence: 90%

“…Considering the results above, the adsorption process can be excluded from the rate-determining step; hence the surface reaction is probably the rate-determining step. Accordingly, it is postulated to simulate the initial concentration (ρ 0 ) dependence of the initial rate (r 0 ) by the modified Langmuir-Hinshewood (L-H) model [25]:…”

Section: Kinetics On the Destruction Of Pyridinementioning

confidence: 99%

“…According to the discussion above, a mechanism based on the L-H kinetic model is advanced here: the photo-catalytic degradation of pyridine on the surface of TiO 2 follows three steps: (1) the absorption of pyridine molecules onto the surface of TiO 2 ; (2) a fast inducement by the irradiation, which includes the produce of electron-hole pairs, hydroxyl radicals and likely oxidants; (3) the opening of pyridine rings during the surface redox reactions. Actually, L-H kinetic model has successfully described many similar photo-catalytic systems [14,20,21,[25][26][27] and generally acknowledged as an essential kinetic equation of heterogeneous photo-catalysis today.…”

Section: Kinetics On the Destruction Of Pyridinementioning

confidence: 99%

See 2 more Smart Citations

Kinetic study on the photo-catalytic degradation of pyridine in TiO2 suspension systems

Zhao

Suo-hong²,

Zhong³

et al. 2004

Catalysis Today

View full text Add to dashboard Cite

Section: Kinetics On the Destruction Of Pyridinementioning

confidence: 90%

Section: Kinetics On the Destruction Of Pyridinementioning

confidence: 99%

Section: Kinetics On the Destruction Of Pyridinementioning

confidence: 99%

See 1 more Smart Citation

Kinetic study on the photo-catalytic degradation of pyridine in TiO2 suspension systems

Zhao

Suo-hong²,

Zhong³

et al. 2004

Catalysis Today

View full text Add to dashboard Cite

“…2. During the photocatalytic degradation of DPAA, TiO 2 absorbed UV light to generate electron-hole pairs (Hong et al, 1998). Then OH• could add on the aromatic group or break the As-C bond and inorganic arsenics, PAA and hydroquinone were ultimately evolved via different oxidation steps.…”

Section: Photodegradation Of Dpaa In Tio 2 Slurry and Possible Degradmentioning

confidence: 99%

Diphenylarsinic acid contaminated soil remediation by titanium dioxide (P25) photocatalysis: Degradation pathway, optimization of operating parameters and effects of soil properties

Wang

Teng

et al. 2016

Science of The Total Environment

View full text Add to dashboard Cite

Diphenylarsinic acid (DPAA) is formed during the leakage of arsenic chemical weapons in sites and poses a high risk to biota. However, remediation methods for DPAA contaminated soils are rare. Here, the photocatalytic oxidation (PCO) process by nano-sized titanium dioxide (TiO 2 ) was applied to degrade DPAA in soil. The degradation pathway was firstly studied, and arsenate was identified as the final product. Then, an orthogonal array experimental design of L 9 (3) 4 , only 9 experiments were needed, instead of 81 experiments in a conventional one-factor-at-a-time, was used to optimize the operational parameters soil:water ratio, TiO 2 dosage, irradiation time and light intensity to increase DPAA removal efficiency. Soil:water ratio was found to have a more significant effect on DPAA removal efficiency than other properties. The optimum conditions to treat 4 g soil with a DPAA concentration of 20 mg kg −1 were found to be a 1:10 soil: water ratio, 40 mW cm −2 light intensity, 5% TiO 2 in soil, and a 3-hour irradiation time, with a removal efficiency of up to 82.7%. Furthermore, this method (except for a change in irradiation time from 3 to 1.5 h) was validated in nine different soils and the removal efficiencies ranged from 57.0 to 78.6%. Removal efficiencies were found to be negatively correlated with soil Contents lists available at ScienceDirectScience of the Total Environment j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / s c i t o t e n v electrical conductivity, organic matter content, pH and total phosphorus content. Finally, coupled with electron spin resonance (ESR) measurement, these soil properties affected the generation of OH• by TiO 2 in soil slurry. This study suggests that TiO 2 photocatalytic oxidation is a promising treatment for removing DPAA from soil.

show abstract

“…The deleterious effects of chemicals on the earth's ecosystems are a cause for serious concerns. Several of these chemicals, such as azo dyes, herbicides, and pesticides, are actually present in rivers and lakes, and are in part suspected of being endocrine-disrupting chemicals (EDCs) [1][2][3][4]. Although, it is still being discussed whether such chemicals have an influence upon human beings or not, it is necessary to develop efficient techniques for elimination and decomposition of those EDCs from water and wastewater as soon as possible.…”

Section: Introductionmentioning

confidence: 99%

Photocatalytic degradation of bisphenol A as an endocrine disruptor in aqueous suspension using Ag-TiO<SUB align=right>2 catalysts

Selvaraj

2006

IJEP

View full text Add to dashboard Cite

A novel photocatalyst, titanium dioxide (TiO 2 ) deposited with silver (Ag), was prepared by a ultrasonic-assisted sol-gel method and studied for the photocatalytic degradation of endocrine disrupting chemicals such as Bisphenol A (BPA) under UV illumination, in order to determine its photocatalytic properties. A series of Ag-TiO 2 catalysts prepared with different Ag dosage were characterized by SEM, EDX, XRD, XPS, and UV-Visible absorption spectroscopy and their photocatalytic activity was evaluated in the degradation of BPA in aqueous suspension.The experiment demonstrated that the presence of Ag in TiO 2 catalysts could enhance the photocatalytic oxidation of BPA in aqueous suspension. It was found that the degradation of BPA by these catalysts followed the first-order kinetic model. The mechanism of the photocatalytic degradation of BPA in this study indicated that the nanosized Ag deposits on TiO 2 particles acted as the sites of electron accumulation where the reduction of adsorbed species such as oxygen occur. The enhanced reduction of oxygen through better electron-hole separation in Ag-TiO 2 particles compared to pure TiO 2 particles increased the rates of BPA degradation. In the reaction of BPA degradation, the presence of two methyl groups in the BPA structure were initially attacked with . OH and/or . OOH radicals which have strong oxidizing power, and then followed by the cleavage of the two phenyl moieties. Finally, the photomineralisation to CO 2 gas occurred via oxidative processes involving carboxylic acids and aldehydes. However, the photocatalytic remediation of contaminated water environments may present a potential risk of irregular and unanticipated reactions by active oxygen species during the photodecomposition, in which some intermediate products may be even more hazardous than the parent compounds [15][16]. In particular, TiO 2 photocatalysis in aqueous media probably yields a variety of intermediates in uncontrollable radical reactions. Therefore, a safe process of photocatalytic oxidation should not only examine the degradation of substrate compounds during the photoreaction, but also monitor the mineralization of the substrate organics as well.In the present study, a series of TiO 2 and Ag-TiO 2 catalysts were synthesized by an ultrasonic-assisted sol-gel method and their photocatalytic activity was evaluated in the photocatalytic degradation of BPA in aqueous suspension. Experimental MaterialsTetra-n-butyl titanate (Ti(O-Bu) 4 ) and silver nitrate (AgNO 3 ) with analytical grade were purchased from Aldrich Chemical Company., USA and used as titanium and silver sources for the preparation of TiO 2 and Ag/TiO 2 photocatalysts. BPA (2,2-bis(4-hydroxyphenyl) propane) with analytical grade was obtained also from Aldrich and used without further purification. The molecular structure of BPA is shown in Fig. 1. Deionized doubly-distilled water was used for the preparation of all solutions.[ Preparation of photocatalystsThe silver-deposited TiO 2 samples (Ag-TiO 2 ) were prepared b...

show abstract

Kinetics and products of the TiO2, photocatalytic degradation of 2-chlorobiphenyl in water

Cited by 79 publications

References 18 publications

Kinetic study on the photo-catalytic degradation of pyridine in TiO2 suspension systems

Kinetic study on the photo-catalytic degradation of pyridine in TiO2 suspension systems

Diphenylarsinic acid contaminated soil remediation by titanium dioxide (P25) photocatalysis: Degradation pathway, optimization of operating parameters and effects of soil properties

Photocatalytic degradation of bisphenol A as an endocrine disruptor in aqueous suspension using Ag-TiO<SUB align=right>2 catalysts

Contact Info

Product

Resources

About