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.

Photocatalytic Removal of 2,4-D Herbicide on Lanthanum Oxide-Modified Titanium Dioxide

2015 ◽  
Vol 1112 ◽  
pp. 168-171
Author(s):  
Wai Ruu Siah ◽  
Nur Azmina Roslan ◽  
Hendrik O. Lintang ◽  
Mustaffa Shamsuddin ◽  
Leny Yuliati
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Inductively Coupled Plasma ◽  
Lanthanum Oxide ◽  
Electrochemical Impedance ◽  
Uv Light ◽  
Photogenerated Electron ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
Impregnation Method

Titanium dioxide (TiO2) has been recognized as an active photocatalyst for degradation of various organic pollutants. In this study, in order to improve the photocatalytic activity of TiO2, the effect of lanthanum oxide modification was investigated by using commercial P25 as the benchmark. Lanthanum oxide/P25 TiO2 composites with 0.1, 0.5, 1 and 5 mol% of La loadings were prepared via an impregnation method. The resultant composites were characterized by X-ray diffraction (XRD), UV-Vis absorption spectroscopy, transmission electron microscopy (TEM), inductively coupled plasma optical emission spectrometry (ICP-OES) and electrochemical impedance spectroscopy (EIS). It was confirmed that the addition of lanthanum oxide did not much affect the crystallinity, crystal structure and the morphology of P25 TiO2. The catalytic activities of the lanthanum oxide/P25 TiO2 catalysts were tested by using 2,4-dichlorophenoxyacetic acid (2,4-D) as the test pollutant and UV light as the irradiation source. The reaction was caried out for 1 hour at room temperature and the percentage removal was determined using a UV spectrophotometer. The results showed that La loading was an important factor that influenced the photocatalytic activity of the composites. After 1 hour reaction, the best catalyst with 0.1 mol% of La loading showed 24% higher photocatalytic activity than the unmodified P25 TiO2 catalyst. It is shown by EIS that the enhanced photocatalytic activity of the composites was due to the ability of lanthanum oxide in improving the charge separation of the photogenerated electron-hole pairs in TiO2.

scholarly journals Synthesis and characterization of gold nanoparticles on titanium dioxide for the catalytic photodegradation of 2,4-dichlorophenoxyacetic acid

2018 ◽  
Vol 16 (5) ◽  
Author(s):  
E. Romero Torres ◽  
M. Gutiérrez Arzaluz ◽  
V Mugica Alvarez ◽  
L. González Reyes ◽  
M. Torres Rodríguez ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Titanium Dioxide ◽  
Uv Light ◽  
Anatase Phase ◽  
Precipitation Method ◽  
Dichlorophenoxyacetic Acid ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Average Size ◽  
2,4 Dichlorophenoxyacetic Acid

The photocatalytic degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) using a Au/TiO2 catalyst and ultraviolet (UV) light energy source (9 mW/cm2) discussed. Gold nanoparticles were synthesized by controlled urea reduction and deposited on titanium dioxide (TiO2) by the deposition-precipitation method. The average size of the nanoparticles was 6-8 nm. X-ray diffraction (XRD) characterization confirmed that TiO2 was present in the anatase phase, whereas the presence and particle size of gold were determined by transmission electron microscopy (TEM). The results of the degradation showed that the activity of TiO2 was improved when Au nanoparticles were present on the surface. The reactions were performed at atmospheric pressure and room temperature.

scholarly journals Photocatalytic degradation of the 2,4-dichlorophenoxyacetic acid herbicide using supported iridium materials

2021 ◽  
Vol 12 (1) ◽  
pp. 125-134
Author(s):  
Claudia Patricia Castañeda Martínez ◽  
Ignacio Alfonso Alvarado Ortega ◽  
Hugo Alfonso Rojas Sarmiento ◽  
Francisco Javier Tzompantzi Morales ◽  
José Ricardo Gómez Romero
Keyword(s):  
Photocatalytic Degradation ◽  
Band Gap Energy ◽  
Charge Carriers ◽  
Dichlorophenoxyacetic Acid ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Improved Performance ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Wet Impregnation Method

In this work, the effect of the addition of iridium on TiO2 and Nb2O5 supports obtained by wet impregnation method was evaluated in the photocatalytic degradation of 2,4-dichlorophenoxiacetic acid under UV irradiation. The synthetized materials were analyzed by different techniques in order to determinate their physicochemical properties. In general, it was observed that the addition of iridium modifies the surface area, band gap energy and it enhances the crystallinity of the materials. Besides, an increase in the photoactivity in the degradation of the herbicide was evidenced using the materials modified. However, the Ir/TiO2 photocatalyst possess the best photocatalytic behavior toward the degradation and possible mineralization of the herbicide. The improved performance of the photocatalyst could be argued by the role of the iridium particles as electron collectors favoring the effective separation of the charge carriers and, as consequence, increasing the degradation of the molecule.           

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.

scholarly journals The Complex Compound of Amino Acids With Titanium (III) as a Method to Control and Synthesis of Different Structures of TiO2 Nanoparticles; Usage as Photocatalysts to Oxidize Alcohols to Aldehyde

2021 ◽  
Author(s):  
Yahya Absalan ◽  
Nazanin Noroozi Shad ◽  
Mostafa Gholizadeh
Keyword(s):  
Amino Acids ◽  
Titanium Dioxide ◽  
Uv Light ◽  
Chemical Analyses ◽  
Benzyl Alcohols ◽  
Titanium Dioxide Nanoparticle ◽  
Physical Chemical ◽  
Nitrobenzyl Alcohol ◽  
Different Types ◽  
Full Investigation

Abstract Different types of the amino acids (Glutamine, Glycine, Alanine) were used to coordinate TiCl3 in order to investigating the best precursor for synthesis of TiO2. Also, a full investigation was carried out to synthesis four different structures of TiO2 nanoparticles [TiO2 (A0.8R0.2), TiO2 (A0.6R0.4), TiO2 (Anatase), and TiO2 (Rutile)]. Oxidation of derivatives alcohol to their corresponding aldehyde through the obtained nanoparticles, as a photocatalyst, under UV light was considered to investigate the best structure of TiO2. Different physical-chemical analyses were applied to investigate the result. The result showed that the titanium dioxide nanoparticle, synthesized from glycine was obtained at the least temperature and was chosen as a precursor to synthesis of four different types of TiO2. All the synthesized TiO2 were applied for oxidation of benzyl alcohols into benzaldehyde, as a test, and TiO2 (A0.6R0.4) could give the best result (87% efficiency). Then it was used to oxidize benzyl alcohol, 4-cholorobenzyl alcohol, 4-nitrobenzyl alcohol and 4-methoxybenzyl alcohol to their corresponding aldehyde and efficiency were 74, 92, 87, and 65% respectively.

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