scholarly journals Novel CaMoO4@GO Nanocomposite: Synthesis, Characterization, and Investigation its Photocatalytic Properties

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).

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.


2021 ◽  
Vol 22 (3) ◽  
pp. 595-601
Author(s):  
R.G. Abaszade ◽  
S.A. Mamedova ◽  
F.G. Agayev ◽  
S.I. Budzulyak ◽  
O.A. Kapush ◽  
...  

We have synthesized large scale, thin, transparent graphene oxide (GO) flakes by Hummer’s method and investigated their suitability for fabrication of transparent nanocomposites. The GO flakes were comprehensively characterized by X-ray diffraction, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDX), Raman spectroscopy and Differential Scanning Calorimetry (DSC). X-ray diffraction displayed the peak of graphene oxide at 9°degree, which is characteristic peak of GO in agreement with the literature results. Scanning Electron Microscopy images revealed that thin, transparent, flake form GO with 14,8 µm lateral size and 0,31µm thickness were synthesized. The comparison with literature results show that for the first time, our group could synthesize large scale, thin and more transparent GO flakes by simple Hummer’s method using simple dispersed graphite. EDX measurements indicate the formation of layered structure with oxygen containing functional groups. The intensity ratio between D and G peaks in the Raman spectra proves that less defective GO flakes have been synthesized. The solution ability of the synthesized material indicate that high quality GO flakes were synthesized, which make them effective soluble material due to oxygen containing groups formed on the graphene plane during synthesis process.DSC results shows that these flakes are thermally stable till 200°C.  Due to high solubility properties, large scale and transparency they can be very useful in fabrication of high optical transparent nanocompoties for replacement indium tin oxide transparent conductors in solar panels, biomedical applications and microwave absorbers for electromagnetic interference (EMI) environmental protection.


2017 ◽  
Vol 10 (04) ◽  
pp. 1750040 ◽  
Author(s):  
Xiaoyun Hao ◽  
Junyan Gong ◽  
Lizhen Ren ◽  
Dongen Zhang ◽  
Xin Xiao ◽  
...  

The polyaniline/bismuth oxybromide (PANI/BiOBr) hybrids materials have been synthesized hydrothermally in the presence of PANI. The PANI/BiOBr hybrids materials were confirmed by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy and ultraviolet–visible diffuse reflectance spectroscopies. Among the hybrid photocatalysts, PANI/BiOBr-0.2 showed the highest photocatalytic properties for the degradation of rhodamine B (RhB), and the increased photocatalytic properties could be due to photosensitization and the inhibited electron–hole recombination.


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.


2013 ◽  
Vol 448-453 ◽  
pp. 730-733
Author(s):  
Si Liang Li ◽  
Ya Jie Guo ◽  
Jing Juan Pu

A novel three-dimensional MnO2 catalyst have been successfully prepared by a facile hydrothermal route. They were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). In addition, they showed excellent catalytic activity over the aqueous degradation of methylene blue (MB).


2015 ◽  
Vol 33 (2) ◽  
pp. 301-305 ◽  
Author(s):  
Girish H. N. ◽  
Basavalingu B. ◽  
Shao G.-Q. ◽  
Sajan C. P. ◽  
S. K. Verma

AbstractGadolinium aluminum perovskite (GdAlO3, GAP) is a promising high temperature ceramic material, known for its wide applications in phosphors. Polycrystalline gadolinium aluminum perovskites were synthesized using a precursor of co-precipitate gel of GdAlO3 by employing hydrothermal supercritical fluid technique under pressure and temperature ranging from 150 to 200 MPa and 600 to 700 °C, respectively. The resulted products of GAP were studied using the characterization techniques, such as powder X-ray diffraction analysis (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM) and energy dispersive analysis of X-ray (EDX). The X-ray diffraction pattern matched well with the reported orthorhombic GAP pattern (JCPDS-46-0395).


2010 ◽  
Vol 13 (1) ◽  
pp. 10-16
Author(s):  
Linh Thi Truc Nguyen ◽  
Tri Huu Nguyen ◽  
Dzung Van Nguyen

The titania coating on phosphate surface was made by the painting method in air and at room temperature. The coatings were dried at 25°c and sintered at 15(TC, 25(FC, 350”C, 45ƠJC, 550°C for 30 minutes. X-ray diffraction, scanning electron microscopy and the cutting method (TCVN 2097-1993) were used to characterize the coatings. The results showed that the coating annealed at 350TC had the high photoactivity in the photodegradation of methylene blue.


Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.


Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.


2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.


Sign in / Sign up

Export Citation Format

Share Document