Photodegradation mechanisms of phenol in the photocatalytic process

Trinh, Dang Trung Tri; Le, Shukun; Channei, Duangdao; Khanitchaidecha, Wilawan; Nakaruk, Auppatham

doi:10.1007/s11164-015-2417-3

Cited by 85 publications

(30 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The same intermediates were detected for all PCD conditions. The nonselective radical reaction pathway is also in good agreement with other reports, e.g., for PCD of ethylbenzene, 81 phenol 37,42,82 or p-cresol, 83 confirming that RCS are insignificantly involved in the degradation path.…”

Section: Resultssupporting

confidence: 91%

Comparative Analysis of Photocatalytic and Electrochemical Degradation of 4-Ethylphenol in Saline Conditions

Brüninghoff

Duijne

Braakhuis

et al. 2019

Environ. Sci. Technol.

View full text Add to dashboard Cite

We evaluated electrochemical degradation (ECD) and photocatalytic degradation (PCD) technologies for saline water purification, with a focus on rate comparison and formation and degradation of chlorinated aromatic intermediates using the same non-chlorinated parent compound, 4-ethylphenol (4EP). At 15 mA·cm –2 , and in the absence of chloride (0.6 mol·L –1 NaNO 3 was used as supporting electrolyte), ECD resulted in an apparent zero-order rate of 30 μmol L –1 ·h –1 , whereas rates of ∼300 μmol L –1 ·h –1 and ∼3750 μmol L –1 ·h –1 were computed for low (0.03 mol·L –1 ) and high (0.6 mol·L –1 ) NaCl concentration, respectively. For PCD, initial rates of ∼330 μmol L –1 ·h –1 and 205 μmol L –1 ·h –1 were found for low and high NaCl concentrations, at a photocatalyst (TiO 2 ) concentration of 0.5 g·L –1 , and illumination at λ max ≈ 375 nm, with an intensity ∼0.32 mW·cm –2 . In the chlorine mediated ECD approach, significant quantities of free chlorine (hypochlorite, Cl 2 ) and chlorinated hydrocarbons were formed in solution, while photocatalytic degradation did not show the formation of free chlorine, nor chlorine-containing intermediates, and resulted in better removal of non-purgeable hydrocarbons than ECD. The origin of the minimal formation of free chlorine and chlorinated compounds in photocatalytic degradation is discussed based on photoelectrochemical results and existing literature, and explained by a chloride-mediated surface-charge recombination mechanism.

show abstract

Section: Resultssupporting

confidence: 91%

Comparative Analysis of Photocatalytic and Electrochemical Degradation of 4-Ethylphenol in Saline Conditions

Brüninghoff

Duijne

Braakhuis

et al. 2019

Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…After reaction in the presence of the cinnamic acid, Figure 7(c), peaks at 2851, 2970 and 2921 cm -1 , assigned to the CH3 symmetric and antisymmetric stretching and the CH2 antisymmetric stretching modes respectively indicate the presence of hydrocarbons at the catalyst surface. 21 There is no evidence for carbonyls between ~1650 -1850 cm -1 , and so the series of peaks lying between 1300 and 1580 cm -1 can also be assigned to vibrations of aromatic C=C, CH3 and CH2 groups from a range of small chain hydrocarbons such as those identified by Dang et al 22 in the mineralisation of phenol. This correlates with the XPS evidence for aromatic groups at the surface although there is no evidence for the aromatic C-H stretching band expected ~ 3070 cm -1 .…”

Section: Effect Of Kcl and Nacl On Intermediates In The Photocatalytic Decomposition Of Cinnamic Acidmentioning

confidence: 98%

The photocatalytic destruction of cinnamic acid and cinnamyl alcohol: Mechanism and the effect of aqueous ions

2020

View full text Add to dashboard Cite

Cinnamic acid was chosen as an exemplar molecule to study the effect of potential contaminants on the kinetics and mechanism of the photocatalytic destruction of hydrocarbons in aqueous solutions. We identify the principal intermediates in the photocatalytic reaction of the acid and corresponding alcohol, and propose a mechanism that explains the presence of these species. The impact of two likely contaminants of aqueous systems, sulfate and chloride ions were also studied. Whereas sulfate ions inhibit the degradation reaction at all concentrations, chloride ions, up to a concentration of 0.5 M, accelerate the removal of cinnamic acid from solution by a factor of 1.6. However, although cinnamic acid is removed, the pathway to complete oxidation is blocked by the chloride, with the acid being converted (in the presence of oxygen) into new products including acetophenone, 2-chloroacetophenone, 1-(2-chlorophenyl)ethenone and 1,2-dibenzoylethane. We speculate that the formation of these products involves chlorine radicals formed from the reaction of chloride ions with the photoinduced holes at the catalyst surface. Interestingly, we have shown that the 1-(2-chlorophenyl)ethenone and 1,2-dibenzoylethane products form from 2chloroacetophenone when irradiated with 365 nm light in the absence of the catalyst. The formation of potentially dangerous side products in this reaction suggest that the practical implementation of the photocatalytic purification of contaminated water needs to considered very carefully if chlorides are likely to be present.

show abstract

“…There are many techniques for treatment of wastewater contaminated with phenolic compounds, including biological processes [5,6], coagulation [7], membranes [8], electro-Fenton and photoelectro-Fenton treatments [9], ozonation [10], oxidation [11,12], and adsorption [13][14][15][16]. However, application of these methods is restricted since they are very expensive and involve high initial capital and operational costs.…”

Section: Introductionmentioning

confidence: 99%

Activated carbon obtained from sapelli wood sawdust by microwave heating for o-cresol adsorption

et al. 2016

View full text Add to dashboard Cite

Activated carbon (AC) was prepared from sapelli wood sawdust using a microwave heating process. The biomass was mixed with inorganic components (lime ? ZnCl 2 and FeCl 3) to form a homogeneous paste. The AC samples are denoted as AC-1A (100 g sapelli wood sawdust ? 20 g lime ? 80 g ZnCl 2), AC-2A (150 g sapelli wood sawdust ? 20 g lime ? 80 g ZnCl 2), AC-1B (100 g sapelli wood sawdust ? 20 g lime ? 40 g ZnCl 2 ? 40 g FeCl 3), and AC-2B (150 g sapelli wood sawdust ? 20 g lime ? 40 g ZnCl 2 ? 40 g FeCl 3). The samples were placed in a microwave oven and pyrolyzed under nitrogen flow. To increase their porosity, the pyrolyzed samples were subjected to a leaching process (with 6 mol L-1 HCl) under reflux to eliminate inorganic components. Several analytical techniques such as Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and N 2 isotherm and vapor adsorption analyses were performed to characterize the AC materials. The samples presented high Brunauer-Electronic supplementary material The online version of this article (

show abstract

Photodegradation mechanisms of phenol in the photocatalytic process

Cited by 85 publications

References 32 publications

Comparative Analysis of Photocatalytic and Electrochemical Degradation of 4-Ethylphenol in Saline Conditions

Comparative Analysis of Photocatalytic and Electrochemical Degradation of 4-Ethylphenol in Saline Conditions

The photocatalytic destruction of cinnamic acid and cinnamyl alcohol: Mechanism and the effect of aqueous ions

Activated carbon obtained from sapelli wood sawdust by microwave heating for o-cresol adsorption

Contact Info

Product

Resources

About