scholarly journals High photocatalytic activity of Fe2O3/TiO2 nanocomposites prepared by photodeposition for degradation of 2,4-dichlorophenoxyacetic acid

2017 ◽  
Vol 8 ◽  
pp. 915-926 ◽  
Author(s):  
Shu Chin Lee ◽  
Hendrik O Lintang ◽  
Leny Yuliati
Keyword(s):  
Photocatalytic Activity ◽  
Uv Light ◽  
Active Species ◽  
High Photocatalytic Activity ◽  
Dichlorophenoxyacetic Acid ◽  
Electron Hole ◽  
And Performance ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Hole Recombination

Two series of Fe2O3/TiO2 samples were prepared via impregnation and photodeposition methods. The effect of preparation method on the properties and performance of Fe2O3/TiO2 for photocatalytic degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) under UV light irradiation was examined. The Fe2O3/TiO2 nanocomposites prepared by impregnation showed lower activity than the unmodified TiO2, mainly due to lower specific surface area caused by heat treatment. On the other hand, the Fe2O3/TiO2 nanocomposites prepared by photodeposition showed higher photocatalytic activity than the unmodified TiO2. Three times higher photocatalytic activity was obtained on the best photocatalyst, Fe2O3(0.5)/TiO2. The improved activity of TiO2 after photodeposition of Fe2O3 was contributed to the formation of a heterojunction between the Fe2O3 and TiO2 nanoparticles that improved charge transfer and suppressed electron–hole recombination. A further investigation on the role of the active species on Fe2O3/TiO2 confirmed that the crucial active species were both holes and superoxide radicals. The Fe2O3(0.5)/TiO2 sample also showed good stability and reusability, suggesting its potential for water purification applications.

Unraveling the quantum dynamics origin of high photocatalytic activity in nitrogen-doped anatase TiO2: time-domain ab initio analysis

2020 ◽  
Vol 8 (47) ◽  
pp. 25235-25244
Author(s):  
Yating Yang ◽  
Zhaosheng Zhang ◽  
Wei-Hai Fang ◽  
Sebastian Fernandez-Alberti ◽  
Run Long
Keyword(s):  
Photocatalytic Activity ◽  
Ab Initio ◽  
Time Domain ◽  
Quantum Dynamics ◽  
High Photocatalytic Activity ◽  
Anatase Tio2 ◽  
Electron Hole ◽  
Nitrogen Doped ◽  
Hole Recombination

TiO2 doping with nitrogen greatly suppresses nonradiative electron-hole recombination and enhances photocatalytic activity.

Photocatalyst Composites of Luminescent Trinuclear Copper(I) Pyrazolate Complexes/Titanium Oxide for Degradation of 2,4-Dichlorophenoxyacetic Acid

2016 ◽  
Vol 846 ◽  
pp. 697-701 ◽  
Author(s):  
Hendrik O. Lintang ◽  
Nur Azmina Roslan ◽  
Noratika Ramlan ◽  
Mustaffa Shamsuddin ◽  
Leny Yuliati
Keyword(s):  
Titanium Oxide ◽  
Dichlorophenoxyacetic Acid ◽  
Electron Hole ◽  
Similar Activity ◽  
Rigid Structure ◽  
Efficient Reduction ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Hole Recombination ◽  
Pyrazole Ligands

Here phosphorescent trinuclear copper (I) pyrazolate complexes ([Cu3Pz3]), synthesized from 3,5-dimethyl and 4-(3,5-dimethoxybenzyl)-3,5-dimethyl pyrazole ligands for complexes [Cu3Pz3]1 and [Cu3Pz3]2, were successfully impregnated into TiO2 with concentration of 0.1 mol%. These luminescent photocatalyst composites ([Cu3Pz3]1or 2/TiO2) gave 60% and 49% of dichlorophenoxyacetic acid (2,4-D) degradation after 1 h for [Cu3Pz3]1/TiO2 and [Cu3Pz3]2/TiO2, while TiO2 only showed 48%. The higher activity observed on [Cu3Pz3]1/TiO2 than the TiO2 would come from the efficient reduction of electron-hole recombination, while less dispersion of complex [Cu3Pz3]2 with more rigid structure compared to complex [Cu3Pz3]1 gave similar activity of the [Cu3Pz3]2/TiO2 to the TiO2.

scholarly journals Study on the synthesis of heterostructure MoS2/TiO2 material for photocatalytic degradation of 2,4-dichlorophenoxyacetic acid

2021 ◽  
Vol 10 (3) ◽  
pp. xx-xx
Author(s):  
Tuan Dao Thi ◽  
Lan Phung Thi ◽  
Mo Nguyen Thi ◽  
Ha Nguyen Ngoc ◽  
Ha Nguyen Thi Thu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Degradation Rate ◽  
Hydrothermal Reaction ◽  
Absorption Capacity ◽  
Argon Atmosphere ◽  
Dichlorophenoxyacetic Acid ◽  
Electron Hole ◽  
Reaction Method ◽  
2,4 Dichlorophenoxyacetic Acid

Nanoflower MoS2, nanowire TiO2(NNW) and 3D MoS2/TiO2 nano-heterostructure have been synthesized successfully by simple typical hydrothermal reaction method followed by 200oC calcination under an argon atmosphere. The prepared samples are characterized in detail by XRD, FESEM, UV-vis DRS, EDX and BET. The results suggest that the TiO2 NNWis successfully coupled with MoS2 to form the heterojunction nanostructure. The hybrid heterostructures can effectively utilize visible-light and solar energy to degrade 2,4-dichlorophenoxyacetic acid (2,4-D). The degradation rate of 2,4-D is as high as 99%. The improved photocatalytic activity owes to the decreased band-gap and the heterosurface properties of MoS2/TiO2, promoting the electron-hole pairs separation and absorption capacity to visible light. This work presents a facile approach for fabricating the MoS2/TiO2 heterostructures for efficient photocatalytic 2,4-D solution, which will facilitate the development of designing photo catalysts applied in environment and energy.

scholarly journals Cobalt Oxide-Modified Titanium Dioxide Nanoparticle Photocatalyst for Degradation of 2,4-Dichlorophenoxyacetic Acid

2017 ◽  
Vol 17 (2) ◽  
pp. 284 ◽  
Author(s):  
Leny Yuliati ◽  
Nur Azmina Roslan ◽  
Wai Ruu Siah ◽  
Hendrik Oktendy Lintang
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Cobalt Oxide ◽  
Uv Light ◽  
Dichlorophenoxyacetic Acid ◽  
Photocatalytic Reaction ◽  
Impregnation Method ◽  
Titanium Dioxide Nanoparticle ◽  
2,4 Dichlorophenoxyacetic Acid

2,4-dichlorophenoxyacetic acid (2,4-D) has been recognized as a possibly carcinogenic compound to human, therefore, 2,4-D should be treated before it is discharged to the environment. Photocatalytic degradation of 2,4-D has been proposed as one of the best methods that offer environmentally safe process. In the present research, titanium dioxide (TiO2) was modified with cobalt oxide (CoO) and tested for photocatalytic degradation of 2,4-D under UV light irradiation. Different amounts of CoO (0.1, 0.5, 1 and 5 mol%) were added onto TiO2 by an impregnation method. The photocatalytic reaction was monitored and analyzed by measurement of 2,4-D absorbance using UV spectrophotometer. After 1 h photocatalytic reaction, it was confirmed that the sample with low loading of 0.1 mol% gave the highest photocatalytic activity among the bare and modified TiO2 photocatalysts. The photocatalytic activity was decreased with the increase of CoO loading, suggesting that the optimum amount of CoO was an important factor to improve the performance of TiO2. Based on fluorescence spectroscopy, such addition of CoO resulted in the reduced emission intensity, which showed the successful decrease in the electron-hole recombination.

scholarly journals Evaluation of electron-hole recombination properties of titanium (IV) oxide particles with high photocatalytic activity

2007 ◽  
Vol 33 (3-5) ◽  
pp. 285-296 ◽  
Author(s):  
Shin-Ya Murakami ◽  
Hiroshi Kominami ◽  
Yoshiya Kera ◽  
Shigeru Ikeda ◽  
Hidenori Noguchi ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
High Photocatalytic Activity ◽  
Electron Hole ◽  
Oxide Particles ◽  
Hole Recombination

Synthesis, Characterization, and Comparison of Sol–Gel TiO2 Immobilized Photocatalysts

2013 ◽  
Vol 11 (2) ◽  
pp. 633-639
Author(s):  
Clara Duca ◽  
Gustavo E. Imoberdorf ◽  
Madjid Mohseni
Keyword(s):  
Photocatalytic Activity ◽  
Composite Coatings ◽  
Sol Gel ◽  
High Photocatalytic Activity ◽  
Dichlorophenoxyacetic Acid ◽  
Titanium Tetraisopropoxide ◽  
Vis Spectroscopy ◽  
Degussa P25 ◽  
Gel Technique ◽  
2,4 Dichlorophenoxyacetic Acid

Abstract This study was focused on the synthesis of titania-based photocatalytic coatings with high photocatalytic activity, attrition resistance, and stability. Five different photocatalytic coatings were synthesized using the sol–gel technique. Three coatings were prepared using aqueous sols of TiO2 nanoparticles with different amounts of titanium tetraisopropoxide and different quantities and types of acids. The other two photocatalysts were composite sol–gel coatings which were prepared by incorporating commercial Degussa P25 into the TiO2 synthesized through sol–gel technique. The physical and optical properties of the immobilized photocatalysts were characterized with UV–vis spectroscopy, X-ray diffraction, scanning electron microscopy, and light scattering. The photocatalytic activity of each coating was determined using a lab-scale differential photoreactor by measuring the degradation rate of a model micropollutant, the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). The conversions of 2,4-D obtained with the TiO2 coatings without Degussa P25 were in the order of 7–23%, whereas the two composite coatings provided conversions in the range of 66–69%. In addition, one of the composite coatings showed a more homogeneous morphology and less cracking, and for this reason, it was more durable and showed lower attrition.

scholarly journals A Review on Recent Progression of Modifications on Titania Morphology and its Photocatalytic Performance

2020 ◽  
Vol 67 (2) ◽  
pp. 361-374
Author(s):  
Nur Farhana Jaafar ◽  
Nur Farhana Jaafar ◽  
Melati Khairuddean ◽  
Norazzizi Nordin
Keyword(s):  
Recent Progress ◽  
Photocatalytic Performance ◽  
Uv Light ◽  
Synthesis Methods ◽  
Light Radiation ◽  
Reactive Site ◽  
Electron Hole ◽  
And Performance ◽  
Hole Recombination ◽  
Degradation Of Pollutants

Titanium dioxide (TiO2) has been broadly used as a photocatalyst because it has good stability and performance for degradation of pollutants. On the other hand, its efficiency as photocatalyst is limited since it can only be excited under UV-light radiation and has a rapid electron-hole recombination that occurs during the photodegradation. There are many studies focusing on adjusting the synthesis methods, addition of dopants and modifying the TiO2 structure to enhance its photocatalytic performance. Among them, synthesis of TiO2 as porous nanoparticles as one of the strategies in modifying the TiO2 structure has gained attention due to its benefits for better adsorption and accessibility of various pollutants onto the reactive site of catalyst, thus enhancing the photocatalytic performance. In this review, we recapitulated on modifications of synthesis methods for TiO2 and their effect on the structure along with the photocatalytic performance. Recent progress for TiO2 in terms of synthesis approaches, effect of dopants, modified structures, and applications are also briefly discussed in this review.

Hydrothermal Synthesis and Photocatalytic Performance of Ag Quantum Dots Sensitized Bi4Ti3O12 Nanobelts

NANO ◽  
2015 ◽  
Vol 10 (02) ◽  
pp. 1550020 ◽  
Author(s):  
Xue Lin ◽  
Xiaoyu Guo ◽  
Di Liu ◽  
Qingwei Wang ◽  
Yongsheng Yan
Keyword(s):  
Quantum Dots ◽  
Photocatalytic Activity ◽  
Rhodamine B ◽  
High Photocatalytic Activity ◽  
Contact Interface ◽  
Electron Hole ◽  
Photoexcited Electron ◽  
Intimate Contact ◽  
Composite Photocatalyst ◽  
Hole Recombination

Ag / Bi 4 Ti 3 O 12 heterostructure with high photocatalytic activity was synthesized via a simple and practical hydrothermal method by using Bi 4 Ti 3 O 12 nanobelts as substrate materials. The as-prepared Ag / Bi 4 Ti 3 O 12 heterostructure included Ag quantum dots assembling uniformly on the surface of Bi 4 Ti 3 O 12 nanobelts. Comparing with pure Bi 4 Ti 3 O 12 nanobelts, the composite photocatalyst exhibited enhanced photocatalytic activity under visible light irradiation in the decomposition of rhodamine B aqueous solution. The enhancement performance is believed to be induced by the intimate contact interface, where silver quantum dots serve as good electron acceptor for facilitating quick photoexcited electron transfer and thus decreasing electron-hole recombination. It was also found that the photodegradation of rhodamine B molecules is mainly attributed to the oxidation action of the generated [Formula: see text] radicals.

The role of a metabolic intermediate in the biodegradation of inhibitory substrates

1997 ◽  
Vol 36 (10) ◽  
pp. 27-36 ◽  
Author(s):  
P. Mungkarndee ◽  
S. M. Rao Bhamidimarri ◽  
A. J. Mawson ◽  
R. Chong
Keyword(s):  
The Other ◽  
Metabolic Product ◽  
Dichlorophenoxyacetic Acid ◽  
Mutual Inhibition ◽  
Metabolic Intermediate ◽  
Batch Cultures ◽  
Ortho Cresol ◽  
2,4 Dichlorophenoxyacetic Acid

Biodegradation of the mixed inhibitory substrates, 2,4-dichlorophenoxyacetic acid (2,4-D) and para-chloro-ortho-cresol (PCOC) was studied in aerobic batch cultures. Each substrate added beyond certain concentrations inhibited the degradation of the other. This mutual inhibition was found to be enhanced by 2,4-dichlorophenol (2,4-DCP) which is an intermediate metabolic product of 2,4-D. When 2,4-DCP accumulated to approximatelY 40 mg/l degradation of all compounds in the mixed 2,4-D and PCOC substrate system was completely inhibited. The degradation of 2,4-D and PCOC individually was also found to be inhibited by elevated concentrations of 2,4-DCP added externally, while PCOC inhibited the utilization of the intermediate.

Sign in / Sign up

Export Citation Format

Share Document