scholarly journals Study of Photocatalytic Activity and Properties of Transition Metal Ions Doped Nanocrystalline TiO2Prepared by Sol-Gel Method

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
K. S. Siddhapara ◽  
D. V. Shah

Transition metal (Mn, Fe, Co,) doped TiO2nanoparticles were synthesized by the sol-gel method. All the prepared samples were calcined at different temperatures like 200°C to 800°C and characterized by X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis. The studies revealed that transition metal (TM) doped nanoparticles have smaller crystalline size and higher surface area than pure TiO2. Dopant ions in the TiO2structure caused significant absorption shift into the visible region. The results of photodegradation of formaldehyde in aqueous medium under UV light showed that photocatalytic activity of TiO2nanoparticles was significantly enhanced by the presence of some transition metal ions. Chemical oxygen demand (COD) of formaldehyde solutions done at regular intervals gave a good idea about mineralization of formaldehyde.

2016 ◽  
Vol 680 ◽  
pp. 193-197
Author(s):  
San Ti Yi ◽  
Si Qin Zhao

TiO2, 1%La/TiO2, 1%Ce/TiO2 and a series of Laand Ce co-doped TiO2 photocatalysts were prepared by sol-gel method. Using sol-gel method combine with hydrothermal method prepared rare earth La, Ce and nitrogen co-doped TiO2 photocatalysts. The microstructure, spectroscopy performance and ion doped form of prepared samples were characterized by X-ray powder diffraction (XRD), UV-Vis diffuse reflectance spectroscopy techniques and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of doped TiO2 were examined by measuring the photodegradation of methyl orange. The results showed that the products were all anatase TiO2 nano powder, doping Laor Cehinder the growth of TiO2 particle, further more, doping Laand Cetogether hinder the growth of TiO2 particle more effective, doping N broaden the light response range of TiO2 photocatalyst. At the same time, the photocatalytic activity results indicated that the prepared samples showed superior UV light photocatalytic activity, the sample 1% (La:Ce,9:1)-N/TiO2 showed the highest UV-vis photocatalytic activity.


2012 ◽  
Vol 562-564 ◽  
pp. 260-264
Author(s):  
Min Zhong ◽  
Jing Jing Yu ◽  
Zhi Hao Wei ◽  
Ping Zhan Si

Pure TiO2 , Ti 0.75 Fe0.25 O2, Ti0.75 Ni0.25 O2, Ti0.75 Co0.25 O2 nanocrystals were prepared by low temperature sol-gel method. The samples were characterized by using transmission electron microscope, X-ray diffractometer and ultraviolet-visible spectrophotometer to study the effect of transition metal ions on the photocatalytic properties of TiO2 nanocrystals. The results show that the pure TiO2 and Ti0.75 Fe0.25 O2, Ti0.75 Ni0.25 O2, Ti0.75 Co0.25 O2 nanocrystals were granular and the size of which is 3.5, 2.9, 3.6, 3.9 nm, respectively. The titania anatase phases appear in the pure TiO2 , the Ti0.75 Fe0.25 O2, Ti0.75 Ni0.25 O2, Ti0.75 Co0.25 O2. The absorption edge of Ti0.75 Fe0.25 O2occur red shift comparing with that of pure TiO2 and the absorption edge of Ti0.75 Fe0.25 O2and Ti0.75 Fe0.25 O2occur blue shift comparing with that of pure TiO2. The photocatalytic properties of pure TiO2, Ti0.75 Fe0.25 O2, Ti0.75 Fe0.25 O2, Ti0.75 Fe0.25 O2nanocrystals synthesized at low temperature by sol-gel method were investigated by degrading the methyl orange solution under ultraviolet irradiation. The degradation rate of Ti0.75 Fe0.25 O2is the highest (60%) and that of Ti0.75Co0.25O2 (10%) is the lowest among these catalysts after degradation for 120min.The result shows that the photocatalytic property ofTi0.75 Fe0.25 O2nanocrystals synthesized at low temperature is obviously better than that of pure TiO2 and Ti0.75 Fe0.25 O2, Ti0.75 Fe0.25 O2.


2011 ◽  
Vol 393-395 ◽  
pp. 1287-1290
Author(s):  
Min Wang ◽  
Qiong Liu ◽  
Qi Xing

The N-doped Cu11O2 (VO4)6 photocatalyst was prepared using the sol-gel method. Techniques of X-ray diffraction (XRD), scanning electron microscope (SEM) have been employed to characterize the as-synthesized materials. During liquid phase photocatalytic degradation of Methy lorange(MO) under the UV-light, the as-prepared N-doped Cu11O2 (VO4)6 exhibits higher activity than the pure Cu11O2 (VO4)6 without doped N. It found that the N-doped Cu11O2 (VO4)6 prepared with the molar ratio of citric acid to metal inons be 2:1, N/Cu molar ratio of 12%, pH=7 and calcinated under 500°C for 4 hours was pure triclinic phase. In this conditions, the sample had highest photocatalytic activity with the photodegradation rate was about 94.42% or so in 60min under 20W ultraviolet lamp.


2013 ◽  
Vol 320 ◽  
pp. 220-225 ◽  
Author(s):  
Xiao Ye Fu ◽  
Xiu Hong Liang

In this paper, we prepared a series of powders (pure TiO2 and Ce-doped TiO2) by sol-gel method and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), infrared spectrometer (IR) and UV spectrophotometer. The results indicated that the doped Ce influence the crystal structure of TiO2 and improve the temperature of crystal transformation. In the degradation of MB experiment, after 5 hours, the degradation efficiency of them (pure TiO2 , Ce-doped TiO2 and P25) under UV light is about 99.1%, while under visible light,Ce-doped TiO2 is about 60% higher than pure TiO2 and P25, up to 73%. This illustrates that the doped Ce increase the absorption to visible light and improve the photocatalytic efficiency.Key Words: TiO2, Ce-doped TiO2, photocatalyst, sol-gel method, crystal form


2013 ◽  
Vol 631-632 ◽  
pp. 399-403
Author(s):  
Xi Ming Luo ◽  
Fen Fen Li ◽  
Hong Tao Gao

Sm, Zr doped nanocrystalline TiO2 powers were prepared successfully by a facile ultrasonic assisted sol-gel method. The products were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. X-ray diffraction peaks could be assigned to anatase TiO2, which confirms the crystallinity of the as-prepared samples. The SEM images demonstrated that the crystalinity is formed with spherical aggregates with average diameters ranging from 10 to 20 nm. The photocatalytic activity was studied on the photocatalytic degradation of methyl orange (MO) aqueous solution irradiated with UV-visible light. Under UV-visible light irradiation, the photocatalytic performances of the doped samples were much better than that of pure TiO2, and the co-dopant showed highest. It demonstrated that a strong Sm-Zr synergistic interaction might play a decisive role in driving the excellent photocatalytic performance of TiO2.


2019 ◽  
Vol 64 (1) ◽  
pp. 61-74 ◽  
Author(s):  
Behnam Khanizadeh ◽  
Morteza Khosravi ◽  
Mohammad A. Behnajady ◽  
Ali Shamel ◽  
Behrouz Vahid

In this study, La and Mg doped, and co-doped ZnO nanoparticles were prepared using the sol-gel method. The prepared samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DRS), and N2 physisorption techniques. The XRD results indicated that the prepared nanoparticles can be well adopted by the hexagonal wurtzite structure crystal and there are no second impurity peaks. Studies of the FESEM, EDX and TEM have shown that the samples have uniform spherical-like morphology with a homogenous distribution. The incorporation of La and Mg into the ZnO lattice had no effect on the morphology of the nanoparticles, but a reduction in the size of the grains (≈ 14 nm to ≈ 7 nm) was observed due to the insertion of these ions. The results of N2 physisorption indicated that there was an increase in BET surface area and pore volume for doped and co-doped samples. The results of DRS showed an increase in band gap energy and a blue shift at the absorption edge for doped and co-doped samples. The photocatalytic activity of the prepared catalysts was evaluated in the removal of RhB under UVA irradiation. The results showed that Mg5%-La5%/ZnO had the highest photoactivity (91.18 %) among all samples.


2014 ◽  
Vol 881-883 ◽  
pp. 256-259
Author(s):  
Hua Fang ◽  
Wei Wu ◽  
Zhun Huang

ZnO photocatalyst was prepared by sol-gel method with the assistance of cetyltrimethylammonium bromide (CTAB). The specific surface area and structure were characterized by Brunauer-Emmett-Teller (BET) method and X-ray diffraction (XRD), respectively. The photocatalytic activity of ZnO prepared for decolorization of methyl orange (MO) aqueous solution was evaluated. The results show that ZnO (mol ratio of ZnO/CTAB is 10) baked at 500°C holds the best photocatalytic activity.


2014 ◽  
Vol 936 ◽  
pp. 819-821
Author(s):  
Yan Huai Zhou ◽  
Xing He Wang ◽  
Jia Chen ◽  
Rui Pu

Cu-N co-doped TiO2powder was prepared by sol-gel method. The Powder was characterized by X-ray diffraction (XRD) and UV-Visible absorbance spectroscopy (UV-Vis). The X-ray results indicated that Cu-N co-doped has no effect on its anatase type. The UV-Vis results show that the absorb threshold has extend to visible-light, the absorbility of co-doped TiO2is higher than that of pure TiO2, and the Photocatalytic activity has been increased.


NANO ◽  
2015 ◽  
Vol 10 (01) ◽  
pp. 1550001 ◽  
Author(s):  
Kui Zhang ◽  
Xiangdong Wang ◽  
Xiaoling Guo ◽  
Jie Dai ◽  
Jingyu Xiang

Mesoporous TiO 2 nanoparticles were synthesized via a fast and classical sol–gel method, respectively. Polyacrylamide was used as the template in the fast sol–gel route; the polymerization crosslink by hydrogen bonds between the template and hydrolysates of Ti alkoxides shortens the reaction time from several days to several hours. The X-ray diffraction results testified that only anatase was obtained in the samples, and the crystallite sizes of the samples prepared by fast and classical sol–gel method were 13.6 nm and 20 nm, respectively. Transmission electron microscopy and N 2 adsorption–desorption reveal that the nanocrystals have typical mesoporous structure and high surface areas. The pore sizes and surface areas of the samples prepared by fast and classical sol–gel method are 17.3 nm and 28.2 nm, 154.7 m2/g and 102.6 m2/g, respectively. The photocatalytic degradation of methyl orange solution under UV light irradiation suggests that the mesoporous TiO 2 photocatalyst prepared by the fast sol–gel method exhibits higher photocatalytic activity than the mesoporous TiO 2 prepared via classical sol–gel method.


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