Investigation on Degradation of Methyl Parathion Using Visible Light in the Presence of Cr+3 and N-Doped TiO2

2010 ◽  
Vol 93-94 ◽  
pp. 280-283 ◽  
Author(s):  
J. Senthilnathan ◽  
Ligy Philip

Nitrogen (N) and Chromium (Cr) doped TiO2 was prepared by sol-gel process. A clear shift in the onset light absorption from UV region (<380) to visible region (>500 nm) was observed for the N-doped samples. The XRD results revealed the decrease in particle size with increasing N content in the lattice of anatase TiO2. Nitrogen doping does not alter the phase of anatase TiO2. The SEM and TEM images of N-TiO2 showed that the particle size is in the range of 20-25nm. The chemical nature of N in the N-TiO2 was evolved through X-ray photoelectron spectroscopy. The presence of different types of N species have been observed corresponding to different oxidation states and the presence of Ti–N and O–Ti–N have been confirmed from the observed binding energy values. Photocatalytic decomposition of methyl parathion was carried out in the visible region and found that N-doped TiO2 showed better catalytic activity than Cr and Cr/N doped TiO2.

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 235
Author(s):  
Hayette Benkhennouche-Bouchene ◽  
Julien G. Mahy ◽  
Cédric Wolfs ◽  
Bénédicte Vertruyen ◽  
Dirk Poelman ◽  
...  

TiO2 prepared by a green aqueous sol–gel peptization process is co-doped with nitrogen and zirconium to improve and extend its photoactivity to the visible region. Two nitrogen precursors are used: urea and triethylamine; zirconium (IV) tert-butoxide is added as a source of zirconia. The N/Ti molar ratio is fixed regardless of the chosen nitrogen precursor while the quantity of zirconia is set to 0.7, 1.4, 2, or 2.8 mol%. The performance and physico-chemical properties of these materials are compared with the commercial Evonik P25 photocatalyst. For all doped and co-doped samples, TiO2 nanoparticles of 4 to 8 nm of size are formed of anatase-brookite phases, with a specific surface area between 125 and 280 m2 g−1 vs. 50 m2 g−1 for the commercial P25 photocatalyst. X-ray photoelectron (XPS) measurements show that nitrogen is incorporated into the TiO2 materials through Ti-O-N bonds allowing light absorption in the visible region. The XPS spectra of the Zr-(co)doped powders show the presence of TiO2-ZrO2 mixed oxide materials. Under visible light, the best co-doped sample gives a degradation of p-nitrophenol (PNP) equal to 70% instead of 25% with pure TiO2 and 10% with P25 under the same conditions. Similarly, the photocatalytic activity improved under UV/visible reaching 95% with the best sample compared to 50% with pure TiO2. This study suggests that N/Zr co-doped TiO2 nanoparticles can be produced in a safe and energy-efficient way while being markedly more active than state-of-the-art photocatalytic materials under visible light.


2012 ◽  
Vol 568 ◽  
pp. 380-383
Author(s):  
Song Tian Li ◽  
Guo Xu He ◽  
Wei Ma ◽  
Yan Hua Liu

In order to expand photoresponse range of TiO2, reduce energy consumption of semiconductor material optical catalytic, certain amount of rare earth element Erbiun was doped during preparation of anatase titanium dioxide to improve the light absorption and photocatalysis efficiency. A series of rare earth element doped TiO2 material were prepared by sol-gel process, and characterized by means of UV-vis diffuse reflectance spectra. UV-vis absorption verified that doping of Er3+ enhanced absorptive capacity of catalyst in visible region. The photocatalytic performance of anatase titanium dioxide and rare earth element Erbiun doped with TiO2 to basic fuchsin were studied.


2022 ◽  
Author(s):  
Monika Patel ◽  
Sunita Mishra ◽  
Ruchi Verma ◽  
Deep Shikha

Abstract Nanotechnology is a completely unique branch of technology that offers with substances in a very small size between (1-100 nm) with various crystal shapes which include spherical nanoparticles, flower shaped, Nano rods, Nano ribbons, and Nano platelets. Metals have ability to produce large number of oxides. These metal oxides play an major role in many areas of chemistry, physics, material science and food science. In this research, Zinc Oxide (ZnO) and Copper (II) oxide nanoparticles were synthesized via sol-gel process using zinc nitrate and copper (II) nitrate as precursor respectively. The characterization of CuO and ZnO nanoparticles was done by using various techniques. X-ray Diffraction (XRD) indicates the crystallinity and crystal size of CuO and ZnO nanoparticle. Fourier transform infrared spectroscopy (FT-IR) was used to get the infrared spectrum of the sample indicating composition of the sample which contains various functional groups. XRD result shows the particle size of CuO at highest peak 29.40140 was 61.25 nm and the particle size of ZnO at highest peak 36.24760 was 21.82 nm. FT-IR spectra peak at 594.56 cm-1 indicated characteristic absorption bands of ZnO nanoparticles and the broad band peak at 3506.9 cm-1 can be attributed to the characteristic absorption of O-H group. The analysis of FT-IR spectrum of CuO shows peaks at 602.09, 678.39, and 730.19cm−1 which refer to the formation of CuO. A broad absorption peak noticed at 3308.2 cm−1 attributed to O–H stretching of the moisture content.


1994 ◽  
Vol 9 (8) ◽  
pp. 2102-2108 ◽  
Author(s):  
E. Haro-Poniatowski ◽  
R. Rodríguez-Talavera ◽  
Heredia M. de la Cruz ◽  
O. Cano-Corona ◽  
R. Arroyo-Murillo

Sols of titania were obtained by the sol-gel method and their size profile was followed by dynamical light scattering. In the early stages of the reaction an unstable behavior was detected. After this unstable regime the particle size reaches a steady state where the sols have a constant size while increasing in number. Once the sol concentration reaches its overlap value, the gelation regime takes place. For samples prepared in this way Raman spectra and x-ray diffractometry were used to characterize the kinetics of crystallization of the material.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaowen Zou ◽  
Xiaoli Dong ◽  
Limei Wang ◽  
Hongchao Ma ◽  
Xinxin Zhang ◽  
...  

Herein, Ni doped ZnO-TiO2composites were prepared by facile sol-gel approach and were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectroscopy (PL). The results indicated that the Ni ions can be incorporated into the lattice of TiO2structure and replace Ti. The introduction of Ni expanded light absorption of TiO2to visible region, increased amount of surface hydroxyl groups and physically adsorbed oxygen (as the electronic scavenges), and then enhanced separation rate of photogenerated carriers. The photodegradation test of reactive brilliant blue (KN-R) under simulated solar light indicated that Ni doped ZnO-TiO2composites have better photocatalytic activities, as compared to those of TiO2and ZnO-TiO2.


2013 ◽  
Vol 787 ◽  
pp. 52-57
Author(s):  
Ying Qiu ◽  
Shu Chun Hu ◽  
Jing Zhai ◽  
Zhi Jian Lin ◽  
Wen Feng Liu ◽  
...  

Silica sphere has wide applications not only in the field of physical chemistry dealing with dynamic behavior and stability of particulate systems, but also in industries including catalysts, ceramics, pigments, pharmacy, etc. However, the control on the particle size is a key factor in the preparation process of silica sphere. In this paper, silica sphere with uniform sphere morphology and amorphous structure was prepared by a sol-gel method, and the control of particle size was emphatically studied. The results showed that the particle size of the as-prepared silica sphere was obviously influenced by the raw materials concentration. The average size of the product increased from 0.66 μm to 0.90 μm when ethanol concentration increased from 7.14M to 9.55M, increased from 0.50 μm to 0.90 μm with the increase of ammonia concentration in the range of 1.88M to 2.36M, and increased from 0.47 to 0.90 μm while tetraethoxysilane concentration increased from 0.08M to 0.11M. Further study indicated that the silica particle size was also influenced by reaction temperature, it increased with the increase of temperature from 26°C to 28°C, and decreased with the further increase of temperature in the scope of 28°C to 32°C.


2014 ◽  
Vol 670-671 ◽  
pp. 113-116 ◽  
Author(s):  
Xiao Yan Zhang ◽  
Xi Wei Qi ◽  
Zhi Yuan Yang ◽  
Rui Xia Zhong

Multiferroic BiFeO3 powders were synthesized by two methods: sol-gel process and hydrothermal method. The synthesized powders were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (SEM) and particle size distribution analysis. The results obtained by XRD, which is consistent with 86-1518 JCPDS card, show that powders prepared by hydrothermal method are composed of the single phase with the trigonal structure (perovskite-type). It can be found by particle size distribution analysis that the particle size of the samples prepared by sol-gel process is finer and more uniform than that of the samples synthesized by the hydrothermal method. The SEM images of samples depicts that the synthesized BiFeO3 powders are united and the average grain size of hydrothermal processed samples is significantly large as compared to the sol-gel derived sample.


2012 ◽  
Vol 455-456 ◽  
pp. 110-114 ◽  
Author(s):  
Xuan Dong Li ◽  
Xi Jiang Han ◽  
Wen Ying Wang ◽  
Xiao Hong Liu ◽  
Yan Wang ◽  
...  

Nb-doped TiO2 powders with different concentrations of Nb have been synthesized by a sol-gel method and characterized by a series of technologies including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy. The photocatalytic activity of Nb-doped TiO2 is evaluated by degradation efficiency of methyl orange in aqueous solution. The results indicate that the photocatalytic activity of Nb-doped TiO2 synthesized with a Nb/Ti molar ratio of 5% is higher than that of TiO2 under the visible light.


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