scholarly journals Preparation and Structural Characterization of Hybrid Composites of Semiconductor Oxides with Amorphous Carbon

2018 ◽  
Vol 912 ◽  
pp. 147-152
Author(s):  
Gabriela Delli Colli Zocolaro ◽  
Gisele S. Silveira ◽  
Marcos A.L. Nobre ◽  
Silvania Lanfredi

Organic/inorganic hybrids composites type have been reported as an alternative for the preparation of multifunctional materials with superior properties to those of individual constituents. In this work, hybrid composites of semiconductor oxides with amorphous carbon (C/ZnO and C/TiO2) were synthesized by partial pyrolysis method and characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The XRD patterns showed the presence of crystalline diffraction lines overlaid by diffraction halos. Infrared spectra showed bands associated to the stretching of Zn-O and Ti-O bonds, as well as bands assigned to the stretching vibrations of C-O, C=O and C-H. Micrographs showed the formation of organized structures in the shape of plates and agglomerates of particles. Structural characterizations showed that the composites present the characteristics of the pristine semiconductors as well of the amorphous carbon matrix, showing a great synergism between C/semiconductor.

2021 ◽  
Vol 12 (4) ◽  
pp. 2523-2529
Author(s):  
Daniel Sam N ◽  
Anish C I ◽  
Sabeena G ◽  
Rajaduraipandian S ◽  
Manobala ◽  
...  

Sol gel methods were used for the study of the antimicrobial activity of Cd-TiO2 against gram-negative and positive bacteria. These Cd-TiO2 have been characterized by various optical and techniques. They have been exhibited by X-ray diffraction, scanning electron microscopy, ultraviolet spectroscopy, and infrared spectroscopy. The structures of the various XRD patterns indicate that the product has a structure. The particle size of Cd-TiO2 is 35nm. The SEM images confirm the spherical appearance of the sample. The energy X-ray spectra have been confirmed as well and then C, O, Ti, Cd, Pt element are present in Cd-TiO2. The weight percentage of Cadmium is 5.8%, Ti is 51.03%, C is 5.13% and O is 31.75% in Cd-TiO2. BET image shows that the major pore size distribution of Cd-TiO2 is ranged from 2.24 nm. The Cd-TiO2 that the antibacterial activity when tested against the pathogens only gram-negative bacteria such as Pseudomonas. The zone of minimum inhibition concentration was measured in a range of 20mm in 25μl and 30mm in 100μl.


1980 ◽  
Vol 24 ◽  
pp. 271-275 ◽  
Author(s):  
John R. Burleson

AbstractIntermediate aluminum oxides (aluminas) have broad X-ray diffraction (XRD) peaks. Many of the phases have similar XRD patterns with overlapping of major peaks. To characterize a multi-component alumina mixture several regions of multiple overlapping peaks are examined. Each region is integrated to a single sum without regard for individual peaks. The integrated regions are applied to various ratio functions obtained from single component standards. By using an iterative technique, the functions converge to yield weight fractions for up to six alumina phases.


Clay Minerals ◽  
1990 ◽  
Vol 25 (3) ◽  
pp. 249-260 ◽  
Author(s):  
A. Plançon ◽  
C. Zacharie

AbstractUntil recently, the determination of the defect structures (previously referred to incorrectly as “crystallinity”) of kaolinites has been obtained in one of two ways: (1) measurement of the Hinckley index, or (2) by comparing calculated X-ray diffraction patterns based on a model of the defect structure (including types of defects and abundances) with experimental diffraction profiles. The Hinckley method is simple and easy to perform but contains no real information about the defect structure. Calculated XRD patterns are based on real defects but these calculations are time consuming and require some skill in application. Another approach is proposed: an expert system which will accurately describe the defect structure of kaolinites based on a few measurements taken from a normal powder diffraction profile. This system has been verified for nine kaolinite samples for which the defect structure was previously determined by comparison of calculated and observed diffraction profiles. The expert system reproduced the correct defect structure for each of the samples.


1995 ◽  
Vol 393 ◽  
Author(s):  
Y. Shao ◽  
S.A. Hackney ◽  
B.C. Cornilsen

ABSTRACTThe crystal structures of the undischarged, heat-treated electrolytic manganese dioxide (HEMD) and discharge products are characterized by high spatial resolution convergent beam electron diffraction (CBED). The results are compared with the x-ray diffraction (XRD) patterns characterized by broad, diffuse peaks. The CBED results for HEMD show that the starting cathodic material has the pyrolusite space group, but with a range of c/a ratios. The variability of the lattice parameter from grain to grain is found to coincide with the broadening on the low angle side of the XRD peaks. The CBED patterns of discharge products suggest a reduction range in c/a ratios and the formation of another phase.


2013 ◽  
Vol 712-715 ◽  
pp. 271-279
Author(s):  
Fei Ding ◽  
Shuang Xi Liu

A new organic silicane which is bridged by a long amino-functionalized alkyl chain was prepared and used as the precursor in the synthesis of a series of PMO materials. The organic silicane was added into the reaction system in CH2Cl2and the PMO materials were prepared by a simple stirring method under acidic condition, with a nonionic surfactantBrij 76 as template. To find the proper synthesis condition, the time of stirring and the proportion of organic silicane and TEOS were varied. Liquid and solid state NMR, X-ray diffraction (XRD) patterns, thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and N2-physisorption properties were used to characterize the structures.


2013 ◽  
Vol 832 ◽  
pp. 596-601 ◽  
Author(s):  
N.A.M. Asib ◽  
Aadila Aziz ◽  
A.N. Afaah ◽  
Mohamad Rusop ◽  
Zuraida Khusaimi

Needle-like zinc oxide (ZnO) nanostructures was deposited on titanium dioxide (TiO2) nanoparticles by solution-immersion method and Radio Frequency (RF) magnetron sputtering with diffferent RF powers, respectively on a glass substrate to synthesis nanocomposites of ZnO/TiO2. Field Emission Scanning Electrons Microscope (FESEM) images demonstrate that needle-like ZnO (112-1110 nm) are deposited on the surface of the TiO2nanoparticles with the diameter of approximately 36.3-62.9 nm. At 200 W, more needle-like ZnO with smallest average diameter (112 nm) appeared on the TiO2nanoparticles, which also has the smallest average size of 36.3 nm The compositions of elements in the nanocomposites were showed by Energy Dispersive X-ray Spectrometry (EDX). All elements of Ti, O, and Zn are observed as major components which confirm the presence of TiO2and ZnO in the composite. X-ray Diffraction (XRD) patterns of the nanocomposites show ZnO formed on TiO2nanoparticles are hexagonal with a wurtzite structure and it revealed ZnO/TiO2thin films were succesfully deposited as nanocomposites of ZnTiO3at 100 W,Zn2TiO4at 150 W and Zn2Ti3O8at 200 W and above.


2020 ◽  
Vol 19 (06) ◽  
pp. 2050012
Author(s):  
Zainab Mefrah Elqahtani ◽  
Soumaya Gouadria ◽  
Fatemah Farraj Alharbi ◽  
K. Omri

In this work, the inorganic/organic a Carbon-Silica (C-S) nanocomposites in additional amorphous carbon matrix was successfully obtained through the sol–gel method, the two components are mixed in an effort to blend the best properties of both. The acquired C-S nanocomposites were characterized by X-ray diffraction (XRD). It was observed by Transmission Electronic Microscopy that nanoparticles with sizes from 14[Formula: see text]nm to 20[Formula: see text]nm. After heat treatment, we explore the electrical properties of the obtained C-S material. The current–voltage ([Formula: see text]–[Formula: see text]) and alternating current (ac) techniques in the temperature range (80–300[Formula: see text]K) was examined.


2020 ◽  
Vol 855 ◽  
pp. 58-63
Author(s):  
Malik Anjelh Baqiya ◽  
Putu Eka Dharma Putra ◽  
Resky Irfanita ◽  
Fitriana ◽  
Darminto ◽  
...  

Non-doped and strontium-doped lanthanum cuprates (La2CuO4 (LCO) and La1.85Sr0.15CuO4 (LSCO15)) in nano-sized particles were synthesized by the chemically dissolved technique employing HNO3 as the dissolving agent. The structural and magnetic properties were investigated by using an x-ray diffraction (XRD) apparatus and a superconducting quantum interference device (SQUID) magnetometer, respectively. The XRD patterns of LCO and LSCO15 show the formation of the single phase without impurities after the calcinations in air at 1100°C for 15 h and the post-annealing in oxygen at 800 °C for 24 h. The average crystallite sizes of LCO and LSCO15 samples were in a range of around 100 nm confirming nano-sized particles. The LCO and LSCO15 nanoparticles exhibit superconductivity at the superconducting (SC) transition temperature, Tc, of 23 K and 38 K, respectively. The magnetization curve measurements have revealed that both samples show the appearance of ferro- and dia-magnetic behavior at room temperature and the appearance of superconductivity at low temperatures. This result may indicate the coexistence of ferromagnetism and superconductivity below Tc in the nano-sized cuprates.


2013 ◽  
Vol 677 ◽  
pp. 94-97 ◽  
Author(s):  
P. Inchidjuy ◽  
Ki Seok An ◽  
S. Pukird

Tin dioxides (SnO2) nanostructure can be grown by vapor transport techniques through a vapor-liquid-solid (VLS) mechanism. The gas flowing have been effect on the evolution of various sizes and shapes of nanostructure materials. The crystalline structures of SnO2materials were investigated by X-ray diffraction (XRD) spectroscopy. XRD patterns of samples exhibited tetragonal phase. The characterization of synthesized products was performed by scanning electron microscopy (SEM). The controlling of process gas flow, showed the various kinds of nanostructures such as nanobelts, nanowires and nanobars of SnO2. The Raman spectra of single-crystalline rutile SnO2nanostructures were studied, the vibration modes were observed corresponded to the typical feature of the SnO2nanostructure. A room temperature photoluminescence (PL) spectrum of SnO2material exhibited visible emission.


2009 ◽  
Vol 421-422 ◽  
pp. 558-561
Author(s):  
Takayuki Kodera ◽  
Kenichi Myoujin ◽  
Takashi Ogihara

Ag and Ni spherical fine powders were continuously produced by carrying out an aerosol process in a mass nanopowder production apparatus. The particles size, particle morphology, crystal phases and crystallinity of the as-prepared powders were characterized by a scanning electron microscope (SEM) and X-ray diffraction (XRD). The particles were nonaggregated and they exhibited a spherical morphology with a narrow size distribution. The average sizes of Ag and Ni particles were 500 nm and 700 nm, respectively. The crystallinity of the as-prepared powders was high. The XRD patterns showed that the crystal phases of the as-prepared powders were the same as those of their respective metals.


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