scholarly journals Kinetics and Mechanism of Aniline and Chloroanilines Degradation Photocatalyzed by Halloysite-TiO2 and Halloysite-Fe2O3 Nanocomposites

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1548
Author(s):  
Beata Szczepanik ◽  
Piotr Słomkiewicz ◽  
Dariusz Wideł ◽  
Marianna Czaplicka ◽  
Laura Frydel
Keyword(s):  
Mass Spectrometry ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Adsorption Equilibrium ◽  
Equilibrium Constants ◽  
First Order ◽  
Photodegradation Rate ◽  
Photodegradation Mechanism ◽  
Kinetics Of ◽  
Commercial Tio2

The kinetics of photocatalytic degradation of aniline, 2-chloroaniline, and 2,6-dichloroaniline in the presence of halloysite-TiO2 and halloysite-Fe2O3 nanocomposites, halloysite containing naturally dispersed TiO2, Fe2O3, commercial TiO2, P25, and α-Fe2O3 photocatalysts, were investigated with two approaches: the Langmuir–Hinshelwood and first-order equations. Adsorption equilibrium constants and adsorption enthalpies, photodegradation rate constants, and activation energies for photocatalytic degradation were calculated for all studied amines photodegradation. The photodegradation mechanism was proposed according to organic intermediates identified by mass spectrometry and electrophoresis methods. Based on experimental results, it can be concluded that after 300 min of irradiation, aniline, 2-chloro-, and 2,6-dichloroaniline were completely degraded in the presence of used photocatalysts. Research results allowed us to conclude that higher adsorption capacity and immobilization of TiO2 and Fe2O3 on the halloysite surface in the case of halloysite-TiO2 and halloysite-Fe2O3 nanocomposites significantly increases photocatalytic activity of these materials in comparison to the commercial photocatalyst: TiO2, Fe2O3, and P25.

scholarly journals Copper oxide supported on graphene for phodegradation of rhodamine B

2015 ◽  
Vol 11 (4) ◽  
Author(s):  
Nurul Sahida Hassan ◽  
Nurul Jamilah Roslani ◽  
Aishah Abdul Jalil ◽  
Sugeng Triwahyono ◽  
Nur Fatien Salleh ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Copper Oxide ◽  
Photocatalytic Degradation ◽  
Rhodamine B ◽  
Industrial Wastewater ◽  
Water Contamination ◽  
X Ray Diffraction ◽  
Composite Photocatalyst ◽  
X Ray ◽  
First Order

In recent years, dyes are one of the major sources of the water contamination that lead to environmental problems. For instance, Rhodamine B (RhB) which was extensively used as a colorant in textile industries is toxic and carcinogenic. Among many techniques, photocatalytic degradation become the promising one to remove those dyes from industrial wastewater. Recently, graphene has shown outstanding performance in this application due to its intrinsic electron delocalisation which promotes electron transport between composite photocatalyst and pollutant molecules. While, copper oxide (CuO) is well-known has a lower bandgap energies compared to other semiconductors. Therefore, in this study, copper oxide supported on graphene (CuO/G) was prepared and its photocatalytic activity was tested on degradation of RhB. The catalysts were characterized by X-Ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) Spectroscopy. The results showed that the interaction between copper and graphene support could enhance the photocatalytic activity. The 5 wt% CuO/G was found to give the highest degradation (95%) of 10 mg L-1 of RhB solution at pH 7 using 1 g L-1 catalyst after 4 hours under visible light irradiation. The photodegradation followed the pseudo first-order Langmuir-Hinshelwood kinetic model. This study demonstrated that the CuO/G has a potential to be used in photocatalytic degradation of various organic pollutants.

scholarly journals Hydrothermal synthesis of cotton-based BiVO4/Ag composite for photocatalytic degradation of C.I. Reactive Black 5

RSC Advances ◽  
2020 ◽  
Vol 10 (64) ◽  
pp. 39295-39303
Author(s):  
Jiangang Qu ◽  
Jiaqi Qian ◽  
Mengtao Wu ◽  
Qinghui Mao ◽  
Min Li
Keyword(s):  
Composite Material ◽  
Photocatalytic Activity ◽  
Hydrothermal Synthesis ◽  
Photocatalytic Degradation ◽  
Reactive Black 5 ◽  
Photodegradation Mechanism ◽  
Excellent Photocatalytic Activity

BiVO4/Ag/cotton-K composite material exhibited excellent photocatalytic activity and recyclability, and the photodegradation mechanism of RB5 by BiVO4/Ag/cotton-K was also proposed.

Kinetics and mechanism of gold(III) incorporation into tetrakis(1-methylpyridium-4-yl)porphyrin in aqueous solution

2004 ◽  
Vol 08 (11) ◽  
pp. 1269-1275 ◽  
Author(s):  
Ahsan Habib ◽  
Masaaki Tabata ◽  
Ying Guang Wu
Keyword(s):  
Aqueous Solution ◽  
Rate Constants ◽  
Kinetic Data ◽  
Ph Dependence ◽  
Equilibrium Constants ◽  
Hydroxyl Group ◽  
Net Charge ◽  
First Order ◽  
Kinetics Of ◽  
Hydrolysis Of

The kinetics of the reaction of the tetrakis(1-methylpyridium-4-yl)porphyrin tetracation, [ H 2( TMPyP )]4+, with gold(III) ions were studied along with equilibria of gold(III) species in aqueous medium at 25°C, I = 0.10 M ( NaNO 3). The equilibrium constants for the formation of [ AuCl 4-n( OH ) n ]- ( n = 0,…,4), defined as β n = [ AuCl 4- n ( OH ) n ]- [ Cl -] n / [ AuCl 4-][ OH -] n were found to be that log β1 = 7.94 ± 0.03, log β2 = 15.14 ± 0.03, log β3 = 21.30 ± 0.05 and log β4 = 26.88 ± 0.05. The overall reaction was first order with respect to each of the total [ Au (III)] and [ H 2 TMPyP 4+]. On the basis of pH dependence on rate constants and the hydrolysis of gold(III), the rate expression can be written as d [ Au ( TMPyP )5+]/ dt = ( k 1[ AuCl 4-] + k2[ AuCl 3( OH )-] + k3[ AuCl 2( OH )2-] + k4[ AuCl ( OH )3-])[ H 2 TMPyP 4+], where k1, k2, k3 and k4 were found to be (2.16 ± 0.31) × 10-1, (6.56 ± 0.19) × 10-1, (1.07 ± 0.24) × 10-1, and (0.29 ± 0.21) × 10-1 M -1. s -1, respectively. The kinetic data revealed that the trichloromonohydroxogold(III) species, [ AuCl 3( OH )]-, is the most reactive. The higher reactivity of [ AuCl 3( OH )]- is explained by hydrogen bonding formation between the hydroxyl group of [ AuCl 3( OH )]- and the pyrrole hydrogen atom of [ H 2( TMPyP )]4+. Furthermore, applying the Fuoss equation to the observed rate constants at different ionic strengths, the apparent net charge of [ H 2( TMPyP )]4+ was calculated to be +3.5.

scholarly journals A study of photocatalytic degradation of textile dye CI basic yellow 28 in water using P160 TiO2 based catalyst

2012 ◽  
Vol 77 (12) ◽  
pp. 1747-1757 ◽  
Author(s):  
Veljko Djokic ◽  
Jelena Vujovic ◽  
Aleksandar Marinkovic ◽  
Rada Petrovic ◽  
Djordje Janackovic ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Textile Dye ◽  
Order Kinetic ◽  
Operational Parameters ◽  
First Order ◽  
Photodegradation Rate ◽  
Vis Spectroscopy ◽  
Langmuir Hinshelwood Mechanism ◽  
Order Kinetic Model ◽  
Alkaline Conditions

The photocatalytic degradation of synthetic textile dye CI Basic Yellow 28 (BY28) in water, using recently synthesized P160 TiO2 based catalyst, under Osram ultra-vitalux? lamp (300 W) light, was studied. The effect of the operational parameters such as initial concentration of catalyst, initial dye concentration and pH was studied. Salt effect was also investigated (NaCl, Na2CO3, Na2SO4, NaNO3). It was found that the optimal concentration of catalyst is 2.0 g L-1. A pseudo first-order kinetic model was illustrated using the Langmuir-Hinshelwood mechanism, and the adsorption equilibrium constant and the rate constant of the surface reaction were calculated (KBY = 6.126 L mg-1 and kC = 0.272 mg L-1 min-1, respectively). The photodegradation rate was higher in weak acidic than in high acidic and alkaline conditions. The presence of CO32- ions increases the photodegradation rate while Cl-, SO42- and NO3-ions decreases the reaction rate. The rate of photodegradation of BY28 was measured using UV-Vis spectroscopy.

scholarly journals Fractional kinetics of photocatalytic degradation

2018 ◽  
Vol 08 (05) ◽  
pp. 1850034 ◽  
Author(s):  
C. L. Wang
Keyword(s):  
Kinetic Model ◽  
Photocatalytic Degradation ◽  
Degradation Process ◽  
Order Kinetic ◽  
Material Parameters ◽  
First Order ◽  
Fractional Kinetics ◽  
Order Kinetic Model ◽  
Kinetics Of ◽  
Degradation Time

In this paper, photocatalytic degradation processes of different materials are fitted to the first-order kinetic model, second-order kinetic model and fractional first-order kinetic model. Deterministic coefficients are calculated for the evaluation of the validity of these models. The fitting results show clearly that the degradation process can fit the fractional first-order kinetic model in a very good manner. In this way, two material parameters can be well defined. One is the degradation time, which can be used to describe the photocatalytic degradation process quantitatively. Another is the order of the derivative, which could be related to the material’s microstructure.

Kinetics of tartrazine photodegradation by UV/H2O2 in aqueous solution

2014 ◽  
Vol 68 (1) ◽  
Author(s):  
Petruta Oancea ◽  
Viorica Meltzer
Keyword(s):  
H2o2 Concentration ◽  
Reaction Intermediates ◽  
Original Design ◽  
Experimental Conditions ◽  
First Order ◽  
Toc Removal ◽  
First Order Kinetics ◽  
Photodegradation Rate ◽  
Pseudo First Order ◽  
Kinetics Of

AbstractIn the present work, kinetics of tartrazine decay by UV irradiation and H2O2 photolysis, and the removal of total organic carbon (TOC) under specific experimental conditions was explored. Irradiation experiments were carried out using a photoreactor of original design with a low-pressure Hg vapour lamp. The photodegradation rate of tartrazine was optimised with respect to the H2O2 concentration and temperature for the constant dye concentration of 1.035 × 10−5 M. Tartrazine degradation and the removal of TOC followed the pseudo-first-order kinetics. The much higher k obs value for tartrazine degradation (7.91 × 10−4 s−1) as compared with the TOC removal (2.3 × 10−4 s−1) confirmed the presence of reaction intermediates in the solution.

scholarly journals Laboratory and Pilot-Plant Scale Photocatalytic Degradation of Polychlorinated Biphenyls in Seawater Using CM-n-TiO2Nanoparticles

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yasser A. Shaban ◽  
Mohamed A. El Sayed ◽  
Amr A. El Maradny ◽  
Radwan Kh. Al Farawati ◽  
Mosa I. Al Zobidi ◽  
...  
Keyword(s):  
Polychlorinated Biphenyls ◽  
Photocatalytic Degradation ◽  
Pilot Plant ◽  
Uv Light ◽  
Catalyst Loading ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Photodegradation Efficiency ◽  
Photodegradation Rate ◽  
Pilot Plant Scale

Photocatalytic degradation of polychlorinated biphenyls (PCBs) in seawater was successfully achieved at laboratory level with UV light and at pilot-plant scale under natural solar radiation using carbon-modified titanium oxide (CM-n-TiO2) nanoparticles. The photocatalytic performance of CM-n-TiO2was comparatively evaluated with reference n-TiO2under identical conditions. As a result of carbon incorporation, significant enhancement of photodegradation efficiency using CM-n-TiO2was clearly observed. To optimize the operating parameters, the effects of catalyst loading and pH of the solution on the photodegradation rate of PCBs were investigated. The best degradation rate was obtained at pH 5 and CM-n-TiO2loading of 0.5 g L−1. The photodegradation results fitted the Langmuir-Hinshelwood model and obeyed pseudo-first-order reaction kinetics.

scholarly journals Impact of TiO2 Nanotubes’ Morphology on the Photocatalytic Degradation of Simazine Pollutant

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2066 ◽  
Author(s):  
Syazwan Meriam Suhaimy ◽  
Chin Lai ◽  
Hairul Tajuddin ◽  
Emy Samsudin ◽  
Mohd Johan
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Tio2 Nanotubes ◽  
Cyanuric Acid ◽  
Catalytic Properties ◽  
Morphological Structure ◽  
Surface Reactivity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Photodegradation Rate

There are various approaches to enhancing the catalytic properties of TiO2, including modifying its morphology by altering the surface reactivity and surface area of the catalyst. In this study, the primary aim is to enhance the photocatalytic activity by changing the TiO2 nanotubes’ architecture. The highly ordered infrastructure is favorable for a better charge carrier transfer. It is well known that anodization affects TiO2 nanotubes’ structure by increasing the anodization duration which in turn influence the photocatalytic activity. The characterizations were conducted by FE-SEM (fiend emission scanning electron microscopy), XRD (X-ray diffraction), RAMAN (Raman spectroscopy), EDX (Energy dispersive X-ray spectroscopy), UV-Vis (Ultraviolet visible spectroscopy) and LCMS/MS/MS (liquid chromatography mass spectroscopy). We found that the morphological structure is affected by the anodization duration according to FE-SEM. The photocatalytic degradation shows a photodegradation rate of k = 0.0104 min−1. It is also found that a mineralization of Simazine by our prepared TiO2 nanotubes leads to the formation of cyanuric acid. We propose three Simazine photodegradation pathways with several intermediates identified.

Photocatalytic Activity of W Doped Ta2O5 Particles for Methylene Blue Degradation under UV-Light

2011 ◽  
Vol 197-198 ◽  
pp. 281-284 ◽  
Author(s):  
Yan Hong Zhao ◽  
Li Chun Hou ◽  
Xiang Li ◽  
Xiaodong Yang ◽  
Xiao Jing Wang
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Uv Light ◽  
Tantalum Oxide ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
Methylene Blue Degradation ◽  
X Ray ◽  
First Order ◽  
Kinetics Of

Tungsten doped tantalum oxide (W-Ta2O5) particles were synthesized by a low temperature hydrothermal method. The phase structure of W-Ta2O5particles was characterized by X-ray diffraction (XRD). The XRD results indicated that the samples belonged to orthorhombic crystal. The photocatalytic activity of samples was investigated with degradation methylene blue (MB) under ultraviolet light. The degradation efficiency of MB under the catalysis of W-Ta2O5particles attained 91% when the reaction time was 7 h. The kinetics of MB degradation was respect to the first-order in the presence of the photocatalysts.

Photocatalytic Degradation of C.I. Reactive Red 2 on the Mixture of TiO2 and HZSM-5 Zeolite

2011 ◽  
Vol 213 ◽  
pp. 1-4
Author(s):  
Li Li ◽  
Bo Yang ◽  
Wen Jie Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Azo Dye ◽  
Adsorption Equilibrium ◽  
Dye Adsorption ◽  
Tio2 Surface ◽  
Reactive Red 2 ◽  
Uv C ◽  
Addition Amount ◽  
Decoloration Rate

A mixture of TiO2 and HZSM-5 zeolite was used for photocatalytic degradation of an azo dye, C.I. Reactive Red 2(RR2). The adsorption of RR2 on TiO2 and the effect of TiO2 concentration were studied. HZSM-5 addition was also investigated to ascertain the function of the zeolite on RR2 decoloration. The results show that, the azo dye is quite stable under exposure of UV-C light. Less than 1.7% of the dye was adsorbed on TiO2 surface and 20 min was needed to reach dye adsorption equilibrium. The optimum TiO2 concentration was 320 mg/l. RR2 adsorption rate increased to more than 40% when HZSM-5 addition amount increased to 0.6 g in the solution. The total decoloration rate increased with the addition of HZSM-5 although zeolite addition could not enhance photocatalytic activity of TiO2.

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