Photocatalytic Properties of WO3 Particles with Different Grain Sizes

2016 ◽  
Vol 697 ◽  
pp. 284-287
Author(s):  
Zhen Guang Shen ◽  
Zhi Jian Peng ◽  
Jing Wen Qian ◽  
Xiu Li Fu

WO3 particles with different grain sizes were prepared by a thermal evaporation method. The composition, morphology, and optical properties of the samples were analyzed by powder X-ray diffraction, scanning electron microscopy, and UV–vis absorption and photoluminescence spectroscopy. Their photocatalytic properties were evaluated by decomposing methylene blue in aqueous phase. It was found that the smaller the grain size of the prepared WO3 particles, the better the degradation effect on methylene blue.

2017 ◽  
Vol 2017 ◽  
pp. 1-4 ◽  
Author(s):  
Swati Arora ◽  
Vivek Jaimini ◽  
Subodh Srivastava ◽  
Y. K. Vijay

Bismuth telluride has high thermoelectric performance at room temperature; in present work, various nanostructure thin films of bismuth telluride were fabricated on silicon substrates at room temperature using thermal evaporation method. Tellurium (Te) and bismuth (Bi) were deposited on silicon substrate in different ratio of thickness. These films were annealed at 50°C and 100°C. After heat treatment, the thin films attained the semiconductor nature. Samples were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM) to show granular growth.


2012 ◽  
Vol 535-537 ◽  
pp. 481-485 ◽  
Author(s):  
Mang Jiang ◽  
Jun Hong Duan ◽  
Zhiang Liu

The authors present the results of hetero-epitaxial growth of ultrafine SnO2nanowires on ZnS nanobelt substrates by a simple thermal evaporation method. ZnS/SnO2hetero-nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS), transmission electron microscopy (TEM) to obtain the morphology and structural information. Comparing with ZnS nanobelts and SnO2nanowires respectively, the optical properties of ZnS/SnO2hetero-nanostructures are studied by Raman scattering and photoluminescence (PL) spectroscopy at room temperature.


Author(s):  
Seyed Mostafa Hosseinpour Mashkani

The current study aims to synthesize and characterize Calcium Molybdate-Graphene Oxide (CaMoO4@GO) nanocomposite under ultrasonic irradiation. Primarily, degradation of Methylene blue (MB) under Uv-Vis light was investigated to measure the photocatalytic properties of the as-synthesized CaMoO4@GO nanocomposite. In addition, various graphene oxide concentrations were applied to investigate its impact on the optical and photodegradation properties of calcium molybdate. X-ray diffraction (XRD), scanning electron microscopy (SEM), and spectra energy dispersive analysis of X-ray (EDS) were used to characterize CaMoO4@GO nanocomposite. DRS results demonstrated that GO influenced significantly the optical properties of CaMoO4 as much as band gap of CaMoO4@GO nanocomposite shows a redshift in comparison with pure CaMoO4. Consequently, photocatalytic results demonstrated that adding GO causes to increase photodegradation of MB form 65% (CaMoO4) to 89% (CaMoO4@GO).


2021 ◽  
Vol 1039 ◽  
pp. 398-405
Author(s):  
Munira M.J. Al-Haji ◽  
Raad M.S. Al-Haddad

Bulk Germanium monosulphide (GeS) alloy was synthesized using the usual melt-quenching technique. Its grains were used as the source material to deposit thin films by vacuum thermal evaporation. Thin-films samples were doped with 1, 2, and 3 at.% indium by thermal co-evaporation and annealed in a vacuum at temperatures 373, 473 and 550 K for an hour. Compositional, structural, and morphological properties of the bulk GeS alloy and its thin films were investigated by Energy Dispersive X-Ray Spectroscopy (EDS), X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM) techniques. The analyses verified the stoichiometry (GeS) of the starting material in the prepared thin films. They also revealed that the thin films under study are amorphous, homogeneous, without any cracks deposited uniformly on the glass substrate with thickness 650 to 700 nm.


2020 ◽  
Vol 44 (7-8) ◽  
pp. 471-474
Author(s):  
Azadeh Jafari ◽  
SAA Terohid ◽  
Alireza Kokabi ◽  
Amir Moradiani

Using a direct oxidation method in a horizontal quartz tube, copper oxide nanowires are grown on a Cu substrate. In order to investigate the growth temperature effects on the structural, morphological, electrical, and photocatalytic properties of the copper oxide nanowires, X-ray diffraction, scanning electron microscopy, a KEITHLEY 2361 system, and a homemade photoreactor are used. The X-ray diffraction results show that both CuO and Cu2O phases are formed, and while increasing the growth temperature, the crystallinity is improved and the intensity of most of the diffraction peaks increases. The scanning electron microscopy images at different growth temperatures show that the number, density, and length of the copper oxide nanowires on pre-formed micro-scaled grains increase, when the growth temperature increases to 700°C and sharper nanowires with average diameters of 1–3 µm grow on the surface. Also I–V curves show that by raising the growth temperature, the conductivity of the samples increases. In addition, the photocatalytic activities are studied by photocatalytic degradation of Congo red dye, and based on these results, the sample grown at 700°C with the highest number and density of the nanowires showed the best photocatalytic performance and electrical conductivity. The results can be used to guide better understanding of the growth behavior of copper oxide nanowires and can be useful for the development of novel photocatalytic nanodevices.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Rohan S. Dassanayake ◽  
Erandathi Rajakaruna ◽  
Noureddine Abidi

Borax-cross-linked guar gum-manganese dioxide (GGB-MnO2) composite was synthesized using an environmentally friendly synthesis route and investigated for its efficiency of decolorizing methylene blue (MB) dye solution by an ultraviolet-visible (UV-Vis) spectrophotometric study. The GGB-MnO2 composite was characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA). The composite (1.2 g/L) exhibited excellent oxidative decolorization of MB (30 mg/L, 50 mL) solution to over 99% in 6, 13, and 40 min at pH 4, 7, and 10, respectively. The complete decolorization of MB occurred via a catalytic adsorption-oxidation-desorption mechanism. The GGB-MnO2 composite showed very good reusability and was stable after ten successive cycles with negligible losses of the decolorization efficiency.


2008 ◽  
Vol 55-57 ◽  
pp. 209-212 ◽  
Author(s):  
Theerachai Bongkarn ◽  
P. Panya

(Pb0.925Ba0.075)TiO3 (PBT) ceramics have been prepared using a mixed oxide technique. The phase formation and morphology were studied in detail via X-ray diffraction (XRD) and scanning electron microscopy (SEM). The pure tetragonal perovskite structure was discovered with calcination temperatures above 800 oC. The percentage of perovskite phase and particle size tends to increase with the increasing of calcination temperatures. The PBT ceramics sintered at various temperatures belonged to a pure tetragonal perovskite phase. The average grain sizes increased from 0.90 to 6.44 µm with the increase of sintering temperatures from 1100 to 1200 oC. The highest density was obtained from the sample that sintered at 1150 and 1200 oC


2016 ◽  
Vol 850 ◽  
pp. 742-747
Author(s):  
Xiang Zhang ◽  
Ping Yun Li ◽  
Xiao De Guo ◽  
Ting Yan

Ultrafine alumina powders were synthesized through pyrocatechol and resorcinol mediated sol-gel process. Aluminum nitrate was applied as the Al source and PVP was the dispersant. X-ray diffraction (XRD) study displayed that γ-Al2O3 powders formed in the range of 800-900 °C, and then γ-Al2O3 transformed to α-Al2O3 at higher temperatures, pure α-Al2O3 powders could be obtained at 1000 °C by using resorcinol as organic monomer. The results of transmission electron microscopy (TEM) revealed that Al2O3 nanoparticles with γ crystalline phase had grain sizes in the range of 5-40 nm. Scanning electron microscopy (SEM) observation displayed that the morphology of the prepared α-Al2O3 powders had aggregated bodies formed by Al2O3 grains in the range of 0.2-0.5μm. These results provide a new way of preparation of alumina powders.


2020 ◽  
Vol 8 (1) ◽  
pp. 93-100
Author(s):  
Ediman Ginting Suka ◽  
◽  
Ira Sudarsono Putri ◽  
Reka Puspitasari ◽  
Reza Arsela ◽  
...  

Composite of rice husk and asphalt silica was carried out at a ratio of 1: 0.7; 1: 0.8 and 1: 0.9 and heated at 150oC for 3 hours. The characteristics of the phase structure, microstructure, and functional groups were analyzed using X-ray Diffraction (XRD), Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) and Fourier Transform Infrared (FTIR), physical properties analysis (density, porosity) and mechanics (compressive strength). The XRD results showed that the phase in asphalt silica composites detected amorphous carbon at 2θ = 18º and amorphous silica with the amorphous silica peak shifted from 2θ = 22º to 2θ = 20º. Microstructure analysis shows that cracks and clusters are bigger with grain sizes of 7,742 µm, 8,495 µm and 10,921 µm respectively, and the sample composition shows percentage of silicon (Si), Oxygen (O) and sodium (Na), respectively. decreases and the percentage of carbon (C), sulfur (S) increases. The results of FTIR show that the functional groups of Si-OH, Si-O-Si and Si-O bonds are decreasing and the functional groups of C-H bonds are increasing. The addition of asphalt causes the value of density increases, the value of porosity and compressive strength decreases.


2011 ◽  
Vol 311-313 ◽  
pp. 319-322 ◽  
Author(s):  
Liang Xiong ◽  
Guo Qing Zhang ◽  
Hua Geng Pan

The Ni-P-TiO2 coatings were successfully obtained on foamed nickel by electroless plating technique. Materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive analysis (EDS) studies. The degradation effect of the prepared coating for the dyes was studied at the same time. Results showed that the appearances of coatings were fine and the amount of TiO2 in the coatings reached at 9.85wt%. The specimens exhibited excellent photocatalytic activity, the decolorization ratio of reactive black GR and methylene blue reached to 92.40% and 95.27% after 4 hours and 6 hours respectively irradiated by the same ultraviolet lamp.


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