scholarly journals Preparation of mesoporous ammonium phosphotungstate/silica catalyst and study on the degradation performance of chlorothalonil

2020 ◽  
Author(s):  
Wei Tan ◽  
Yifei Zhang ◽  
Tianli Wang ◽  
Lei Liu ◽  
Junxiu Ye ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Raw Materials ◽  
Aquatic Toxicity ◽  
Sol Gel ◽  
Water System ◽  
Ammonium Bromide ◽  
Alcohol Water ◽  
Ft Ir ◽  
Cetyl Trimethyl Ammonium ◽  
Degradation Effect

Abstract Chlorothalonil is widely used to control fungal diseases and it is usually detected in the environment. Phototransformation is an important process to remove chlorothalonil from the aquatic environment. The mesoporous ammonium phosphotungstate/silica catalyst (NH4PW/SiO2) was synthesized from cetyl trimethyl ammonium bromide (CTAB) and tetraethoxysilane (TEOS) as raw materials by adding insoluble ammonium phosphotungstate into the alkaline alcohol–water system by the sol-gel method. The structure of NH4PW/SiO2 was characterized by X-ray diffractometry (XRD), Brunauer–Emmett–Teller (BET) and Fourier transform infrared spectroscopy (FT-IR). The photocatalytic activity of NH4PW/SiO2 was evaluated by using the organic pesticide chlorothalonil as a model reactant. The result indicated that when the dosage of NH4PW/SiO2 is 0.02 g, the illumination is 180 min, the concentration of chlorothalonil is 5 mg/L, pH = 5, the degradation effect is better, and the degradation rate reaches 83.23%. The results contributed to the understanding of chlorothalonil phototransformation and the potential of mesoporous SiO2 to effectively enhance the photocatalytic activity of NH4PW (64.16%) to reduce aquatic toxicity and pollution by chlorothalonil.

scholarly journals Preparation and photocatalytic activity analysis of nanometer TiO2 modified by surfactant

2018 ◽  
Vol 8 ◽  
pp. 184798041878197 ◽  
Author(s):  
Wenzheng Wu ◽  
Longjian Zhang ◽  
Xiaojie Zhai ◽  
Ce Liang ◽  
Kaifeng Yu
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Anatase Phase ◽  
Sol Gel ◽  
Sodium Dodecyl ◽  
Sodium Dodecyl Benzene Sulfonate ◽  
Ammonium Bromide ◽  
Transmission Electron ◽  
Cetyl Trimethyl Ammonium ◽  
Nano Titanium Dioxide

Combining the advantages of the sol–gel method and solvothermal method, the single anatase phase of nano-titanium dioxide (TiO2) with high crystallinity had been prepared by means of the sol–solvent thermal improved process, in which butyl titanate was used as titanium source; anhydrous ethanol as solvent; concentrated nitric acid as inhibitor; and cationic surfactant cetyl trimethyl ammonium bromide (CTAB), anionic surfactant sodium dodecyl benzene sulfonate (SDBS), and nonionic surfactant polyethylene glycol (PEG) as dispersants. The analysis results of Brunauer–Emmett–Teller, scanning electron microscopy, and transmission electron microscopy characterizations indicated that CTAB-modified TiO2 with the optimum ratio had the most apparent dispersibility and the highest specific surface area compared with unmodified TiO2, SDBS-modified TiO2, and PEG-modified TiO2. At the same time, the photocatalytic degradation rate of methyl orange could be improved to 99.16%. It indicated that the modification effect of CTAB was significantly better than those of SDBS and PEG, which made the nanoparticles uniformly dispersed, resulting in higher photocatalytic activity.

Preparation of La–TiO2/Bentonite and Its Photodegradation Properties to Cyanide

2016 ◽  
Vol 16 (4) ◽  
pp. 4233-4238
Author(s):  
Qinglong Wang ◽  
Kexun Chen ◽  
Yali Zhang
Keyword(s):  
Waste Water ◽  
Photocatalytic Activity ◽  
Raw Materials ◽  
Sol Gel ◽  
Molar Ratio ◽  
Nitrate Hexahydrate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Scanning Electron

The photocatalytic materials were prepared by sol–gel method: the main raw materials were tetrabutyltitanate and the lanthanum nitrate hexahydrate, bentonite was the carrier to support TiO2.The properties of the composites were characterized by specific surface area (BET), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and thermogravimetric analysis (TG). The photocatalytic degradation of cyanide waste water was used to assess the photocatalytic activity of the materials. The experimental results showed that the suitable content of lanthanum and roasted temperature could improve the photocatalytic activity. When the composites were roasted at 400 °C and the molar ratio of La to Ti was 1%, the photocatalyst reached optimal performance.

Preparation and Characterization of Nano-Porous SiO2/TiO2-SiO2 Thin Films on Glass Substrates by Sol-Gel Method

2012 ◽  
Vol 531-532 ◽  
pp. 651-654
Author(s):  
Qing Nan Zhao ◽  
Ying Liu ◽  
Shao Hong Hou ◽  
Wu Zeng ◽  
Jie Sun
Keyword(s):  
Surface Morphology ◽  
Raw Materials ◽  
Sol Gel ◽  
Amorphous Structure ◽  
Tetrabutyl Titanate ◽  
Ammonium Bromide ◽  
Gel Method ◽  
Sol Gel Method ◽  
Glass Substrates ◽  
Cetyl Trimethyl Ammonium

Nano-porous bilayers structure antireflection films on glass substrate were prepared by sol-gel method, tetraethyl orthosilicate(TEOS) and tetrabutyl titanate(TEOT) as the main raw materials, cetyl trimethyl ammonium bromide(CTAB) and polyethylene glycol(PEG) as template. The relation of the template agent addition, pH, and aging time to surface morphology and optical properties were analyzed. When the CTAB/TEOS = 1/30, the average spectral transmittance in the visible wavelength is 93.69% and the peak transmission is up to 97.37%. All the bilayers antireflection films are amorphous structure, uniform surface morphology, dense nano-porous size distribution, pore size is about 10nm.

scholarly journals Controllable Hydrothermal Synthesis and Photocatalytic Performance of Bi2MoO6 Nano/Microstructures

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1161
Author(s):  
Tao Ji ◽  
Enna Ha ◽  
Mingzhou Wu ◽  
Xin Hu ◽  
Jie Wang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Facile Hydrothermal Route ◽  
Nanoparticle Aggregates ◽  
Electron Microscopes ◽  
Cetyl Trimethyl Ammonium ◽  
Scanning Electron Microscopes

Bi2MoO6 with a tunable morphology was synthesized by a facile hydrothermal route using different surfactants, including nanosheet-assembled microspheres, smooth microspheres, nanoparticle aggregates and nanoparticles. The morphology, crystal structure and photocatalytic activity of as-obtained Bi2MoO6 were characterized by scanning electron microscopes (SEM), X-ray diffraction (XRD), photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) and UV–Vis spectrophotometer. Bi2MoO6 flower-like microspheres using cetyl-trimethyl-ammonium bromide (BET) as the surfactant exhibited much better photocatalytic activity than Bi2MoO6 with the other morphologies, with a degradation efficiency of 98.4%. It can be summarized that the photocatalytic activity of Bi2MoO6 samples depends on their morphology and composition.

Preparation of CNTs/TiO2/CS Film and its Photocatalytic Activity

2011 ◽  
Vol 287-290 ◽  
pp. 1607-1611
Author(s):  
Li Ping Zeng ◽  
Quan Zhang ◽  
Guo Qiang Zhang ◽  
Li Hui Zou
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Sol Gel ◽  
Synergetic Effect ◽  
Structure And Property ◽  
Catalyst Film ◽  
Photocatalytic Activities ◽  
Ft Ir ◽  
Gaseous Formaldehyde ◽  
Carbon Nano Tube

In this work, carbon nano-tube/TiO2(CNTs/TiO2) nanocomposites were prepared using a conventional sol-gel method. To further obtain a uniform catalyst film, chitosan (CS) was used as a crosslinker for the CNTs/TiO2composite. The structure and property of CNTs/TiO2/CS film were characterized using XRD, FT-IR, TEM, SEM, and UV-vis. The photocatalytic activities of CNTs/TiO2/CS film were measured through the photocatalytic degradation of gaseous formaldehyde. Compared with the commercial TiO2, higher degradation was achieved with the CNTs/TiO2/CS film due to stronger absorbability and synergetic effect among CNTs, TiO2, and CS.

Experimental and Theoretical Studies of Thermophysical Properties of MgO-Water Nanofluid

2020 ◽  
Vol 1008 ◽  
pp. 47-52
Author(s):  
Abdallah Yousef Mohammed Ali ◽  
Ahmed Hassan El-Shazly ◽  
Marwa Farouk El-Kady ◽  
Hesham Ibrahim Elqady ◽  
Kholoud Madih ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermophysical Properties ◽  
Volume Fraction ◽  
Sol Gel ◽  
Solid Volume Fraction ◽  
Ammonium Bromide ◽  
Distilled Water ◽  
Step Method ◽  
Mgo Nanoparticles ◽  
Cetyl Trimethyl Ammonium

Magnesium oxide (MgO) nanoparticles were synthesized using the sol-gel technique then characterized. Cetyl Trimethyl Ammonium Bromide (CTAB) surfactant was added to reduce Van der Waal forces among MgO nanoparticles and distilled water forming a stable nanofluid using two-step method with aid of ultrasound sonication. Pure distilled water and nanofluids with different volume fractions of 0.25, 0.5, 0.75, and 1% are used as working fluids. Thermophysical properties of prepared nanofluids were measured experimentally and determined theoretically. Effect of solid volume fraction on the thermophysical properties; including thermal conductivity, heat capacity, viscosity, and density of MgO-water nanofluids are discussed. Moreover, experimental results have been compared with the suitable correlations for MgO-water nanofluid. The findings show that thermal conductivity, viscosity, and density of nanofluid increases with increasing solid volume fraction.

Synthesis of V2O5 Powders by EDTA Assistance Ultrasound Sol-Gel Process

2012 ◽  
Vol 512-515 ◽  
pp. 207-210
Author(s):  
Quan Wen ◽  
Jian Feng Huang ◽  
Li Yun Cao ◽  
Jian Peng Wu
Keyword(s):  
Activation Energy ◽  
Raw Materials ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Calcination Temperatures ◽  
Sol Gel Process ◽  
Ft Ir ◽  
Precursor Powders ◽  
Influence Of Ph

V2O5 powders were successfully synthesized by the EDTA assistanced ultrasound sol-gel process using NH4VO3 and EDTA, NH3•H2O as raw materials. The synthesized activation energy and the influence of pH values and the calcination temperatures on the phases and microstructures of powders were particularly investigated. The precursor powders and the V2O5 powders were characterized by X-ray diffraction (XRD), fourier transform inelectron microscopy (FT-IR), scanning electron microscopy (SEM) and differential scanning calorimetry-thermal gravimetric (DSC-TG). Results show that the obtained products exhibit good crystallization under the conditions of pH=4, calcination temperature 400~500 °C and calcination time 0.5 h during the synthesizing process. The as-prepared V2O5 powders show preferred growth orientation along (001) plane at the pH=4. By DSC analysis, the ultrasonic cavitation result in the decrease in synthesized activation energy obviously than that was prepared without ultrasonic irradiation.

Preparation and Characterization of Nanocrystalline La2Ti2O7 by Microwave Assisted Process

2016 ◽  
Vol 852 ◽  
pp. 525-529 ◽  
Author(s):  
Ying Zhou ◽  
Zhi Yong Mei ◽  
Hai Shao Ye ◽  
Wen Wen Su ◽  
Xi Zhao ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Uv Light ◽  
Raw Materials ◽  
Spherical Shape ◽  
High Photocatalytic Activity ◽  
X Ray Diffraction ◽  
Microwave Assisted ◽  
Average Grain Size ◽  
Ft Ir

Using La (NO3)3·6H2O, TiCl4 , and citric acid as the main raw materials, nanocrystalline La2Ti2O7 samples were prepared by microwave assisted method. The structure and morphology of samples were characterized by thermogravimetric and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier Transform Infrared (FT-IR) spectroscopy. The photocatalytic activity of La2Ti2O7 was studied for methyl orange (MO) used as simulated sewage. It was found that the single phase La2Ti2O7 could be obtained through the calcination of microwave processed La2Ti2O7 precursors at 600 °C. The resulted product had an approximate spherical shape and average grain size of 50 nm in diameter. Under UV light, the photocatalytic experiment indicated that the prepared La2Ti2O7 nanocrystalline had high photocatalytic activity for degradation of methyl orange.

Porous SiO2/SiC Fiber Via Carbothermal-Reduction of Hybrid Fiber in Air Flows

2011 ◽  
Vol 236-238 ◽  
pp. 1492-1496
Author(s):  
Qiu Sheng Song ◽  
Kai Zhang ◽  
Shun Xu ◽  
Zhen Biao Zhong ◽  
Meng Li
Keyword(s):  
Sintering Temperature ◽  
Raw Materials ◽  
Sol Gel ◽  
Drawing Process ◽  
Hybrid Fiber ◽  
Hybrid Fibers ◽  
Air Atmosphere ◽  
Sic Fiber ◽  
Different Temperatures ◽  
Ft Ir

Using tetraethoxysilane (TEOS) and novolac-PF as raw materials, SiO2/PF hybrid fibers were prepared via sol-gel associated with drawing process, and then sintered at different temperatures (500-1300 °C) under air atmosphere. The microstructure variation and reaction mechanism of the fiber were investigated by FT-IR, XRD, and SEM measurements. The results showed that the microstructure variation of the hybrid fiber was influenced greatly by sintering temperatures. When the sintering temperature was below 900 °C, the fibers were amorphous, and converted into porous SiO2/SiC fibers after being sintered at 1300 °C.

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