scholarly journals Effect of Various Additives on Photocatalytic Degradation of 4-Nitrophenol

2009 ◽  
Vol 6 (s1) ◽  
pp. S422-S428 ◽  
Author(s):  
Kashif Naeem ◽  
Feng Ouyang
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Degradation ◽  
Rice Husk ◽  
Uv Light ◽  
Aqueous Suspension ◽  
Degradation Efficiency ◽  
Optimal Amount ◽  
Supporting Materials ◽  
Better Than

The photocatalytic degradation of 4-nitrophenol (4-NP) assisted by titanium dioxide (TiO2) was investigated in aqueous suspension under irradiation by UV light. The effect of different supporting materials mixed physically with TiO2on the photocatalytic degradation of 4-NP has been studied. TiO2with all supports exhibits good degradation efficiency of 4-NP and was better than TiO2alone. The addition of SiO2and ZSM-5 only caused a little change in 4-NP degradation. However, degradation of 4-NP was improved from 34.89% to 60.53% within 120 min photocatalysis in the presence of optimal amount of AC. The degradation was also fairly enhanced in the presence of cheaper rice husk and the activity was closed to AC.

scholarly journals Preparation and Properties of CaCO3-Supported Nano-TiO2 Composite with Improved Photocatalytic Performance

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3369
Author(s):  
Jie Wang ◽  
Sijia Sun ◽  
Lei Pan ◽  
Zhuoqun Xu ◽  
Hao Ding ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Photocatalytic Performance ◽  
Uv Light ◽  
Interaction Mechanism ◽  
Pure Tio2 ◽  
Degradation Efficiency ◽  
Nano Tio2 ◽  
Composite Photocatalyst ◽  
Tio2 Particles ◽  
Grinding Machine

In order to improve the photocatalytic degradation efficiency of nano-TiO2, reduce its usage and realize recycling and reuse, CaCO3–TiO2 composite photocatalyst was prepared with calcium carbonate (CaCO3) and TiO2 in a grinding machine through the integration of grinding depolymerization, dispersion and particle composition. The photocatalytic degradation performance, recycling performance, structure and morphology of CaCO3–TiO2 were studied. The interaction mechanism between CaCO3 and TiO2 and the improvement mechanism for the photocatalytic performance of TiO2 were also discussed. The results show that under the UV light irradiation for 20 and 40 min, the degradation efficiency of methyl orange by the composite photocatalyst with 40% TiO2 (mass fraction) was 90% and 100%, respectively. This was similar to that of pure TiO2, and the performance of the composite photocatalyst was almost unchanged after five cycles. CaCO3–TiO2 is formed by the uniform loading of nano-TiO2 particles on the CaCO3 surface, and the nano-TiO2 particles are well dispersed. Due to the facts that the dispersion of nano-TiO2 is improved in the presence of CaCO3 and the charge transport capability is improved through the interfacial chemical bonds between CaCO3 and TiO2, the formation of this complex is an intrinsic mechanism to improve the photocatalytic efficiency of nano-TiO2 and reduce its usage in application processes.

The Photocatalytic Properties of Br-Doped Titania Nanotube Arrays and its Application in Degradation of Sugar Wastewater

2013 ◽  
Vol 641-642 ◽  
pp. 11-17 ◽  
Author(s):  
Zhi Peng Meng ◽  
Fu Xin Zhong ◽  
Dan Yu Wang ◽  
Zhong Ming Zhang ◽  
Hua Ying Li ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Degradation ◽  
Uv Light ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Photocatalytic Properties ◽  
Nanotube Arrays ◽  
Illumination Time ◽  
Novel Approach ◽  
Titanium Dioxide Nanotube Arrays

This paper presents a novel approach for preparing titanium dioxide nanotube arrays (TNTs) loaded with highly dispersed Br through an ultrasound aided photochemical route. The content of Br doped on the arrays was controlled by changing the concentration of NaBr and the ultrasound time. The Br doped TiO2nanotube arrays were characterized by SEM, XRD and UV–Vis spectrum. Doping the bromine did not basically affect the morphology of the surface of the TNTs, but part of the anatase phase transformed into rutile phase, which led to the formation of the mixed crystal and increased the photocatalytic activity. The results showed that Br doping significantly enhanced the photocatalytic degradation rate of titanium dioxide nanotube arrays under UV-light irradiation. The main factors which affected photocatalytic degradation of sugar wastewater were the illumination time and pH. The results showed that the longer the exposure time was, the initial pH of wastewater was more favorable to photocatalytic degradation of the sugar wastewater for the Br-TiO2nanotube arrays, and compared to undoped TiO2nanotube arrays Br doped TiO2nanotube arrays had better photocatalytic properties.

scholarly journals Direct photolysis and photocatalytic degradation of 2-amino-5-chloropyridine

2003 ◽  
Vol 68 (12) ◽  
pp. 961-970 ◽  
Author(s):  
Biljana Abramovic ◽  
Vesna Anderluh ◽  
Andjelka Topalov ◽  
Ferenc Gaal
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Degradation ◽  
Uv Light ◽  
Parent Compound ◽  
Analytical Techniques ◽  
Direct Photolysis ◽  
Pyridine Moiety ◽  
Initial Substrate ◽  
Zero Order Reaction ◽  
Degradation Reaction

The direct photolysis and photocatalytic degradation of a pyridine pesticide analogue, 2-amino-5-chloropyridine, were investigated employing different analytical techniques ? potentiometry, for monitoring the pH and chloride genera- tion, spectrophotometry, for studying the degradation of the pyridine moiety, ion chromatography, for monitoring nitrate formation, and total organic carbon analysis for investigating the efficiency of the process. The photocatalytic degradation was studied in aqueous suspensions of titanium dioxide under illumination by UV light. It was found that chloride evolution was a zero-order reaction which takes place by direct photolysis, in that way differing from the degradation of the pyridine moiety, which takes place in the presence of titanium dioxide. Changes in pH during degradation indicate the formation of acidic intermediates and nitrate in addition to chloride. The effect of the initial substrate concentration was also investigated by monitoring the reaction of chloride generation as well as the degradation reaction of the pyridine moiety. It was found that degradation of the parent compound (2.5 mmol/dm3) by direct photolysis is completed in about 20 minutes, and of the pyridine moety by photocatalytic degradation in about nine hours. Based on the obtained data a possible reaction mechanism is proposed.

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.

Porous ceramic foam loading titanium dioxide for photocatalytic degradation of the methyl orange solution

2019 ◽  
Vol 15 (6) ◽  
pp. 1366-1378
Author(s):  
Y.J. Guo ◽  
W. Cheng ◽  
P.S. Liu
Keyword(s):  
Titanium Dioxide ◽  
Methyl Orange ◽  
Photocatalytic Degradation ◽  
Porous Ceramic ◽  
Degradation Efficiency ◽  
Ceramic Foam ◽  
Raw Material ◽  
Polymer Foam ◽  
Content Type ◽  
Wide Range

Purpose The purpose of this paper is to provide an investigation on a new kind of photocatalytic material, namely, the porous ceramic foam loading titanium dioxide, which can make an effective photocatalytic degradation of the methyl orange (MO) solution in the wastewater. Design/methodology/approach The natural zeolite powder has been used as the primary raw material to produce a sort of lightweight porous ceramic foam by impregnating polymer foam in slurry and then sintering. With the sol-gel method, a kind of open-cell reticular porous ceramic foam loading TiO2 film was obtained having a good photocatalytic action, and the resultant porous composite product presents the bulk density of 0.3~0.6 g/cm3 to be able to float on water. Findings The MO could tend to be completely degraded in the solution with a certain concentration by the TiO2-loaded ceramic foam irradiated with ultraviolet light, and this composite foam was found to have high degradation efficiency for the MO solution in a wide range of pH. Originality/value This work presents a TiO2-loaded ceramic foam that can effectively photo-catalyze to degrade the MO in water, and the degradation efficiency were examined under different conditions of the MO solution with various pH values.

Photocatalytic degradation of atenolol in aqueous suspension of new recyclable catalysts based on titanium dioxide

2017 ◽  
Vol 5 (4) ◽  
pp. 3224-3234 ◽  
Author(s):  
Marco Tammaro ◽  
Valeria Fiandra ◽  
Maria Cristina Mascolo ◽  
Antonio Salluzzo ◽  
Chiara Riccio ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Degradation ◽  
Aqueous Suspension ◽  
Recyclable Catalysts

Photocatalytic Degradation Activity of TiO2 Nanotubes for Cr(VI)

2013 ◽  
Vol 864-867 ◽  
pp. 715-718 ◽  
Author(s):  
Xiang Qing Li ◽  
Zhen Hong ◽  
Shi Zhao Kang ◽  
Li Xia Qin ◽  
Guo Dong Li ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Calcination Temperature ◽  
Uv Light ◽  
Degradation Efficiency ◽  
Light Irradiation ◽  
Uv Light Irradiation ◽  
Degradation Activity ◽  
The Stability

TiO2 nanotubes were obtained by calcining at various temperatures. The influence of calcination temperature on the degradation activity of TiO2 nanotubes for Cr (VI) was investigated under UV light irradiation. It was found that the photocatalytic activity of TiO2 nanotubes calcinated at 350 °C was the highest. Furthermore, the photocatalytic activity of TiO2 nanotubes was higher than that of the P25 TiO2 nanoparticles. Importantly, the stability of TiO2 nanotubes for the degradation of Cr (VI) was high, and degradation efficiency can still reach 72.4% after 8 recycles. Consequently, a highly stable and active photocatalyst for degradation of Cr (VI) was achieved.

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