Fast Sol–Gel Method to Prepare Mesoporous TiO2 with High Photocatalytic Activity

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.

2020 ◽  
Vol 7 (2) ◽  
pp. 191590 ◽  
Author(s):  
A. K. Azfar ◽  
M. F. Kasim ◽  
I. M. Lokman ◽  
H. A. Rafaie ◽  
M. S. Mastuli

Ag and Ni/ZnO photocatalyst nanostructures were successfully synthesized by a sol–gel method. In this work, the photocatalyst sample was systematically studied based on several factors affecting the performance of photocatalyst, which are size, morphology, band gap, textural properties and the number of active sites presence on the surface of the nanocatalyst. X-ray diffraction revealed that Ag/ZnO nanomaterials experienced multiple phases, meanwhile for Ni/ZnO the phase of nanomaterials were pure and single phase for stoichiometry less than 5%. Field emission scanning electron microscope (FESEM) showed almost all of the synthesized nanomaterials possessed a mixture of nanorods and spherical-like shape morphology. The Ag/ZnO showed high photocatalytic activity, producing at least 14th trials of nanocatalyst reusability on degradation of methyl orange under UV irradiation. Interestingly, this phenomenon was not observed in larger surface area of Ni/ZnO nanomaterials which supposedly favour photocatalytic activity, but instead producing poor photocatalytic performance. The main reasons were studied and exposed by temperature-programmed desorption of carbon dioxide (TPD–CO 2 ) which showed that incorporation of Ag into ZnO lattice has enhanced the number of active sites on the surface of the nanocatalyst. Whereas incorporation of Ni in ZnO has lowered the number of active sites with respect to undoped ZnO. Active sites measurement is effective and significant, providing opportunities in developing an intensive study as an additional factor.


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.


2011 ◽  
Vol 214 ◽  
pp. 6-10
Author(s):  
Wen Jie Zhang ◽  
Ke Xin Li ◽  
Yang Yu

The ammonia phosphate treated HZSM-5 zeolite was used as support for TiO2 prepared by sol-gel method. Adsorption and photocatalytic activity of the zeolite, adsorption of the loaded TiO2, and the optimum TiO2 loading percentage were studied. The zeolite can concentrate methyl orange solution after adsorbing water and possesses no obvious photocatalytic activity. The solution reached its adsorption equilibrium after 20 min when using TiO2 loaded on HZSM-5. In the TiO2 loading range from 10% to 70%, the dye decoloration rate increased constantly from 20% to 36.2%. The activity of the TiO2 was enhanced after loading with the optimum loading percent of 70%. During the whole 180 min of irradiation, TiO2/HZSM-5 showed enhanced methyl orange decoloration activity.


2019 ◽  
Vol 15 (4) ◽  
pp. 398-406 ◽  
Author(s):  
Charfeddine Messaadi ◽  
Taher Ghrib ◽  
Jalila Jalali ◽  
Mondher Ghrib ◽  
Alanood Abdullah Alyami ◽  
...  

Background: The photocatalytic activity of SnO2-TiO2 nanocomposites was successfully assessed after synthesis by Sol-Gel method, deposition on porous silicon material and annealing at 400, 600 and 800oC temperatures, with surface grain size in the range between 5 and 12 nm. The photocatalyst was characterized by X-ray diffraction (XRD), high resolution scanning electron microscopy (SEM), thermogravimetric analysis (TGA), derivative thermogravimetry (DTG) and mass spectroscopy (MS). The photocatalytic assessment suggests that this SnO2-TiO2 photocatalyst presents important photocatalytic efficiency to methyl blue (MB) at low annealing temperature. </P><P> Methods: In this work, sol-gel method is used to prepare SnO2-TiO2 nanocomposites; which were deposited on porous silicon, annealed at different temperatures and investigated to understand their structural, morphological, optical and physical properties. Their photocatalytic activity was evaluated by using the degradation of MB under irradiation with UV light. </P><P> Results: The intensity of the characteristic absorption band of methyl blue at 655 nm decreased significantly with the increasing irradiation time. Meanwhile, a change in color of the solution occurred; turning from blue to colorless after 20 min of irradiation, and thus indicating the gradual decomposition of methyl blue molecules during UV light irradiation in the presence of the prepared SnO2-TiO2. As expected, no degradation of the SnO2-TiO2 nanocomposites occurred under control experimental conditions. The MB degradation efficiency was reported by C/C0 quantity; where C and C0 correspond respectively to its concentration at time t and initial concentration. In the presence of photocatalysts, it can be clearly deduced that after irradiation for 20 min, the C/C0 of the MB value was about 0% with the prepared and untreated nanocomposites of SnO2-TiO2 and remains constant when using a SnO2-TiO2 nanocomposite treated at 800°C. </P><P> Conclusion: This research has successfully synthesized the SnO2-TiO2 nanocomposite photocatalysts by Sol-Gel process and deposited by spin–coating technique on porous silicon substrates. Besides, all structural, optical and catalytic properties were studied and CO related. The obtained material was annealed at three different temperatures 400&#176;C, 600&#176;C and 800&#176;C. It is denoted that its grain size increases from about 5 nm to 12 nm with the annealing temperature. The photocatalytic effect has been tested on the MB solution, which demonstrates that the nanometric grain size enhances the adsorption properties and achieves a good photocatalytic performance at a low temperature.


2011 ◽  
Vol 361-363 ◽  
pp. 1598-1601
Author(s):  
Min Wang ◽  
Qiong Liu ◽  
Hai Yan Luan

Cu11O2 (VO4)6 powders have been synthesized by complexing Sol-Gel method using citric acid as chelate, calcined at different temperature without using any template. Techniques of X-ray diffraction (XRD) and scanning electron microscope (SEM) have been employed to characterize the as-synthesized materials. The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange (MO) solution under UV-light. It revealed that temperature values can influence significantly on the morphologies and structures of the products.It also found that the sample prepared with the molar ratio of citric acid to metal inons be 2:1, pH=7 and calcinated under 500°C for 4 hours was pure triclinic Cu11O2 (VO4)6 phase.In this conditions, the sample had highest photocatalytic activity with the photodegradation rate was about 78.9% or so in 60min under 20W ultraviolet lamp.


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.


2020 ◽  
Vol 52 (5) ◽  
Author(s):  
Oumaima Mertah ◽  
Kenza El Hajjaji ◽  
Abdelali El Gaidoumi ◽  
Adil Lachehab ◽  
Hicham Hassoune ◽  
...  

2013 ◽  
Vol 390 ◽  
pp. 552-556 ◽  
Author(s):  
Torpong Kreetachat ◽  
Jittiporn Kruenate ◽  
Kowit Suwannahong

Biodegradable of polylactic acid (PLA), polybutylene adipate-co-terephthalate (PBAT) and polybutylene succinate (PBS), which were biodegradable aliphatic polyesters, composite films were contained with titanium dioxide (TiO2) as a photocatalyst to evaluate the photocatalytic activity of bidegradable composite films for toluene removal. The synthesized TiO2 was prepared by sol-gel method between titanium isopropoxide with acetic acid. To form the anatase structure, it was calcined at 500°C. TiO2 were added to PLA/PBAT/PBS as a biopolymer blend at 0, 5 and 10 wt% .The TiO2/Bio-composite films were fabricated via blown film technique to produce 40 μm films. Photocatalytic activity efficiency of TiO2/Bio-composite films was performed in an annular closed system under UV light. Since the amount of TiO2 affected the efficiency of the photocatalytic activity, this work was mainly concentrated on the effort to embed the high amount of TiO2 in the biopolymer matrix. The developed photocatalyst was characterized by XRD, UV-Vis spectrophotometer and SEM. The SEM images revealed the high homogeneity of the deposition of TiO2 on the biopolymer matrix. The X-ray diffraction (XRD) ensures the deposition of TiO2 as crystalline anatase phase. In addition, the photocatalytic results shown that the toluene removal efficiencies increased with an increasing TiO2 dosages at 0 wt%, 5 wt%, and 10 wt% , respectively. As aspects, the photocatalytic degradation results showed the highest tolune photocatalytic degradation efficiency of 52.0% at 10 wt% TiO2 .


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