Facile Preparation of Cadmium Gallate Nanoparticles as a Novel Photocatalyst with High Efficiency and Stability

2019 ◽  
Vol 11 (5) ◽  
pp. 678-682
Author(s):  
Ce Liang ◽  
Nian Tao ◽  
Bowen Wang ◽  
Wenjun Liu ◽  
Ke Bi ◽  
...  

In this work, we introduced a facile approach for preparing cadmium gallate (CdGa2 O4 nanoparticles, and we first studied the photocatalytic properties of this ternary spinel oxide. Through a solvothermal process for the formation of precursor and the subsequent calcination process for recrystallization, CdGa2 O4 nanoparticles with diameter of ca. 12 nm were synthesized. They were characterized by using X-ray diffraction patterns and electron microscopy images. UV-visible diffuse absorption spectroscopy was also conducted; its spectra indicate that CdGa2 O4 nanoparticles have strong but small blue-shift absorption relative to that of the bulk samples. Moreover, the CdGa2 O4 nanoparticles could photocatalytically decompose rhodamine B (RhB) molecules with high efficiency in aqueous solution under ultraviolet irradiation. Notably, this novel photocatalyst exhibited outstanding recycling stability, and it retained almost the same capacity in the fourth photocatalytic cycle. We deduce that the high photocatalytic performance results from the large specific surface area, energetic photoinduced carriers, and inherent stability.

2015 ◽  
Vol 68 (8) ◽  
pp. 1293 ◽  
Author(s):  
Pakvipar Chaopanich ◽  
Punnama Siriphannon

Hydroxyapatite (HAp) nanoparticles were successfully synthesized from an aqueous mixture of Ca(NO3)2·4H2O and (NH4)2HPO4 by a facile single-step refluxing method using polystyrene sulfonate (PSS) as a template. The effects of reaction times, pH, and PSS concentration on the HAp formation were investigated. It was found that the crystalline HAp was obtained under all conditions after refluxing the precursors for 3 and 6 h. The longer refluxing time, the greater the crystallinity and the larger the crystallite size of the HAp nanoparticles. The HAp with poor crystallinity was obtained at pH 8.5; however, the well-crystallized HAp was obtained when reaction pH was increased to 9.5 and 10.5. In addition, the X-ray diffraction patterns revealed that the presence of PSS template caused the reduction of HAp crystallite size along the (002) plane from 52.6 nm of non-template HAp to 43.4 nm and 41.4 nm of HAp with 0.05 and 0.2 wt-% PSS template, respectively. Transmission electron microscopy images of the synthesized HAp revealed the rod-shaped crystals of all samples. The synthesized HAp nanoparticles were modified by l-aspartic acid (Asp) and l-arginine (Arg), having negative and positive charges, respectively. It was found that the zeta potential of HAp was significantly changed from +5.46 to –24.70 mV after modification with Asp, whereas it was +4.72 mV in the Arg-modified HAp. These results suggested that the negatively charged amino acid was preferentially adsorbed onto the synthesized HAp surface.


2019 ◽  
Vol 34 (3) ◽  
pp. 242-250 ◽  
Author(s):  
J. Anike ◽  
R. Derbeshi ◽  
W. Wong-Ng ◽  
W. Liu ◽  
D. Windover ◽  
...  

Structural characterization and X-ray reference powder pattern determination have been conducted for the Co- and Zn-containing tridymite derivatives Ba(Co1−xZnx)SiO4 (x = 0.2, 0.4, 0.6, 0.8). The bright blue series of Ba(Co1−xZnx)SiO4 crystallized in the hexagonal P63 space group (No. 173), with Z = 6. While the lattice parameter “a” decreases from 9.126 (2) Å to 9.10374(6) Å from x = 0.2 to 0.8, the lattice parameter “c” increases from 8.69477(12) Å to 8.72200(10) Å, respectively. Apparently, despite the similarity of ionic sizes of Zn2+ and Co2+, these opposing trends are due to the framework tetrahedral tilting of (ZnCo)O4. The lattice volume, V, remains comparable between 626.27 Å3 and 626.017 (7) Å3 from x = 0 to x = 0.8. UV-visible absorption spectrum measurements indicate the band gap of these two materials to be ≈3.3 and ≈3.5 eV, respectively, therefore potential UV photocatalytic materials. Reference powder X-ray diffraction patterns of these compounds have been submitted to be included in the Powder Diffraction File (PDF).


Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1042
Author(s):  
Nikita V. Chukanov ◽  
Anatoly N. Sapozhnikov ◽  
Roman Yu. Shendrik ◽  
Marina F. Vigasina ◽  
Ralf Steudel

Five samples of differently colored sodalite-group minerals from gem lazurite deposits were studied by means of electron microprobe and wet chemical analyses, infrared, Raman, electron spin resonance (ESR) and UV-Visible spectroscopy, and X-ray diffraction. Various extra-framework components (SO42−, S2− and Cl− anions, S3•−, S2•− and SO3•− radical anions, H2O, CO2, COS, cis- as well as trans- or gauche-S4 neutral molecules have been identified. It is shown that S3•− and S4 are the main blue and purple chromophores, respectively, whereas the S2•− yellow chromophore and SO3•− blue chromophore play a subordinate role. X-ray diffraction patterns of all samples of sodalite-group minerals from lazurite deposits studied in this work contain superstructure reflections which indicate different kinds of incommensurate modulation of the structures.


2021 ◽  
Author(s):  
Mohsen Mehrabi ◽  
Mostafa Zahedifar ◽  
soheila hasanloo ◽  
hossein Nikmanesh ◽  
Rouhollah Gheisari ◽  
...  

Abstract Lithium tetraborate nanoparticles co-doped with various percentages of Cu and Mg impurities were synthesized through the combustion process. Scanning electron microscopy images along with X-Ray diffraction pattern confirmed the shape and structure of the products. The Williamson-Hall equation was used to measure the size of nanoparticles that resulted in approximately 47 nm for the crystallite size. The optical band gap of about 3.7 eV was obtained for the nanostructures from the UV-visible spectrum. Furthermore, the thermoluminescence features the samples under gamma irradiation were studied at ambient conditions. The highest thermoluminescence sensitivity achieved at 0.02 % wt Cu and 0.5 % wt Mg impurities simultaneously. The results show that the co-doped nanoparticles have a linear dose response up to an administrated dose of 30 kGy and about 10% of the thermoluminescence signal fades after 30 days of storage at room temperature.


2020 ◽  
pp. 1307-1312
Author(s):  
Wadaa S. Hussein ◽  
Ala' Fadhil Ahmed ◽  
Kadhim A. Aadim

The current study was achieved on the effects of laser energy and annealing temperature on x-ray structural and optical properties, such as the UV-Visible spectra of cadmium sulfide (CdS). The films were prepared using pules laser deposition technique (PLD) under vacuum at a pressure of 2.5×10-2 mbar with different laser energies (500-800 mJ) and annealing at a temperature of 473K. X-ray diffraction patterns and intensity curves for the CdS showed that the formation of CdS multi-crystallization films at all laser energies. The optical properties of the films were studied and the variables affecting them were investigated in relation to laser energy and changes in temperature.


2008 ◽  
Vol 41 (4) ◽  
pp. 738-746 ◽  
Author(s):  
Torsten Weissbach ◽  
Tilmann Leisegang ◽  
Andreas Kreyssig ◽  
Matthias Frontzek ◽  
Jens-Uwe Hoffmann ◽  
...  

A YNi2B2C single crystal containing traces of foreign phases was inspected by means of neutron and X-ray diffraction as well as scanning electron microscopy and X-ray spectroscopy methods. The diffraction patterns obtained from the experiments look similar to those expected for a superstructure. Nevertheless, they can be interpreted as crystallographically oriented precipitations of YB2C2and Ni2B within the YNi2B2C crystal, formed during the cooling process. The orientation relation between the lattices was obtained from experimental neutron and X-ray data. Structure refinements of the collected X-ray data were performed by separation of the intensity data of the individual phases. Scanning electron microscopy images of the inclusions found on a polished cross section of the crystal are presented; their chemical composition was determined using wavelength-dispersive X-ray analysis.


2012 ◽  
Vol 9 (3) ◽  
pp. 1342-1346 ◽  
Author(s):  
K. Basavaiah ◽  
K. Tirumala Rao ◽  
A. V. Prasada Rao

In this work, we report preparation and characterization of dodecylbenzene sulfonic acid (DBSA) doped tetraaniline via micelles assisted method using ammonium per sulphate (APS) as an oxidant. Here, DBSA act as dopant as well as template for tetraaniline nanostructures. The synthesized DBSA doped tetraaniline have been well characterized by X-ray diffraction patterns, Fourier transform infrared spectroscopy, UV-Visible spectroscopy, Scanning electron microscopy and thermogravimetry. The morphologies of tetraaniline were found to be dependent on molar ratios of N-phenyl-1, 4-phenylenediamine to DBSA. The spectroscopic data indicated that DBSA doped tetraaniline. Thermogravimetry studies revealed that the DBSA doping improved the thermal stability of tetraaniline.


2005 ◽  
Vol 888 ◽  
Author(s):  
Jin-Seo Noh ◽  
Dong-Seok Suh ◽  
Sang Mock Lee ◽  
Kijoon H. P. Kim ◽  
Woong-Chul Shin ◽  
...  

ABSTRACTConventional Ge2Sb2Te5 (GST) was modified by adding up a small amount of SiOx, using co-sputtering technique from multiple targets. The SiOx content was gradually increased by increasing the power applied to SiOx target, up to 8 volume percent. The sheet resistance of SiOx-containing GST exponentially increased, when the room-temperature-deposited samples were annealed at 300 °C. Transmission electron microscopy images revealed that no SiOx particulates were formed, which was confirmed by Gattan image filtering. It was indicated by x-ray diffraction patterns that the grain size of SiOx-containing GST is smaller than normal GST with lattice locally distorted at its crystalline state, suggesting that molecular SiOx is homogeneously distributed throughout the GST matrix. We observed that the crystallization temperature of SiOx-containing GST is gradually elevated by increasing the SiOx content, while the melting point decreased. These observations led to the reset current reduction, which is a critical requirement for the high density PRAM.


2019 ◽  
Vol 19 (2) ◽  
pp. 422
Author(s):  
Siham Lhimr ◽  
Saidati Bouhlassa ◽  
Saidati Bouhlassa ◽  
Saidati Bouhlassa ◽  
Bouchaib Ammary ◽  
...  

In this paper we study the effects of different molar ratio R of Zn2+ to OH– (R= nOH–/nZn(II) of the precursor was investigated by varying the amount of NaOH. Samples have been synthesized by the colloidal method at room temperature using (ZnCl2), citric acid (C6H8O9·H2O) and sodium hydroxide (NaOH). The formation of ZnO/C composite was characterized by The X-ray diffraction patterns indicated a high crystallinity and nanocrystalline size of ZnO with hexagonal wurtzite structure. The morphologies of the particles have been studied with a scanning electronic microscopy (SEM). The existence of carbon into the composite was detected by FTIR and EDS. The optical band gap of various ZnO/C composite was calculated from UV-Visible absorption measurement varied in the range 3.301 to 3.282 eV according to R values.


2011 ◽  
Vol 391-392 ◽  
pp. 1392-1395
Author(s):  
Jing Li ◽  
Yong Cai Zhang

A simple and cost-effective method based on the reduction of AgNO3 by H2O2 (5 vol.%) in 2.5–5 vol.% NH3•H2O aqueous solutions at room temperature and under atmospheric pressure was developed for the synthesis of Ag submicron crystallites. X-ray diffraction patterns demonstrated that the resultant products were pure cubic phase Ag powders. Field emission scanning electronic microscopy images showed that the Ag powders synthesized in 2.5 and 5 vol.% NH3•H2O aqueous solutions comprised submicron crystallites with the sizes of about 355–580 and 200–650 nm, respectively. Besides, the possible formation mechanism of Ag powders in the present system was also proposed.


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