Showing papers in "Journal of Materials Science: Materials in Electronics in 2016"
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TL;DR: In this paper, a simple chemical precipitation method in aqueous solution was used to synthesize Ni, Ni(OH)2, NiO nanoparticles as well as Ni/Ni(OH)/NiO nanocomposites, which were characterized by X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), TEM, and Fourier transform infrared (FT-IR) spectroscopy.
Abstract: In this work Ni, Ni(OH)2, NiO nanoparticles as well as Ni/Ni(OH)2 and Ni/NiO nanocomposites were synthesized via a simple chemical precipitation method in aqueous solution. The prepared products were characterized by X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR) spectroscopy. Alternating gradient force magnetometer (AGFM) illustrated ferro-magnetic behaviour of Ni nanoparticles as well as Ni/Ni(OH)2 and Ni/NiO nanocomposites. The photocatalytic behaviour of Ni–NiO nanocomposites was evaluated using the degradation of organic dyes under ultraviolet light irradiation. The results show that Ni–NiO nanocomposites have applicable magnetic and photocatalytic performance.
287 citations
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TL;DR: In this paper, an attempt is made to synthesize the cerium-doped copper ferrite nanoparticles (CuFe2−xCexO4) through an auto-combustion method with the aid of nitrate precursors such as copper(II), iron(III), and cerium(III) in an aqueous solution.
Abstract: In the current study and attempt is made to synthesized the cerium-doped copper ferrite nanoparticles (CuFe2−xCexO4) through an auto-combustion method with the aid of nitrate precursors such as copper(II), iron(III), and cerium(III (in an aqueous solution. Besides, the effect of different concentrations of various type of capping agents such as lactose and glucose on the morphology and particle size of final products was investigated. The structural, morphological, and optical properties of as-obtained products were characterized extensively by techniques such as FT-IR, XRD, EDX, SEM, TEM, and UV–vis. Furthermore, the magnetic property of as-prepared CuFe2−xCexO4 nanoparticles was also investigated with vibrating sample magnetometer at room temperature. Moreover, the as-prepared Ce-doped CuFe2O4 nanoparticles were used as efficient photocatalyst for the photocatalytic degradation of harmful organic dye, i.e. methyl orange under ultraviolet light.
162 citations
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TL;DR: In this paper, the first review about gas sensing properties of α-Fe2O3 nanostructures is presented, in which the authors have extensively reviewed the properties of the material.
Abstract: Interest in detecting and determining concentrations of toxic and flammable gases has constantly been on the increase in recent years due to increase of modernization, industrialization and high standards of life. Detection of such gases is very important in many different fields such as industrial emission control, household and social security, vehicle emission control and environmental monitoring. Metal oxide gas sensors are among most important devices to detect a large variety of gases. α-Fe2O3, an environmental friendly semiconductor (E
g = 2.1 eV), is the most stable iron oxide under ambient atmosphere and because of its low cost, high stability, high resistance to corrosion, and its environmentally friendly properties is one of the most important metal oxides for gas sensing applications. This is the first review about gas sensing properties of α-Fe2O3 nanostructures. In this paper gas sensing properties of α-Fe2O3 are extensively reviewed. After a brief explanation about metal oxide gas sensors and α-Fe2O3, sensors based on α-Fe2O3 nanomaterials have been reviewed. Gas sensing section is divided into five subsections: pure α-Fe2O3 gas sensors, metal/α-Fe2O3 gas sensors, metal oxide/α-Fe2O3 gas sensors, polymer/α-Fe2O3 gas sensors and graphene/α-Fe2O3 gas sensors.
135 citations
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TL;DR: In this paper, a dip-coating technique was employed to prepare anatase phase of titania thin films, which revealed the amorphous and anatase phases of TiO2 for as-synthesized and annealed samples.
Abstract: A dip-coating technique was employed to prepare anatase phase of titania thin films. Fluorine doped tin oxide substrates were used to prepare titania thin films. The samples were annealed at 550 °C for 18 h. X-ray diffraction results revealed the amorphous and anatase phases of TiO2 for as-synthesized and annealed samples, respectively. The crystallite size of anatase TiO2 thin films was almost 25 nm for annealed samples. UV–visible confirmed the energy band gap 3.86 and 3.64 eV for as-prepared and calcinated titania thin films. The reduction in the energy band gap could be due to the change in crystallization and agglomeration of small grains after calcination. The morphology of the prepared films was investigated by field emission scanning electron microscopy which demonstrated the agglomeration of spherical particles of TiO2 with average particle size of about 30 nm. The molecular properties (chemical bonding) of the samples were investigated by means of Fourier Transform Infrared (FTIR) spectroscopy. FTIR analysis exhibited the formation of titania, functional group OH, hydroxyl stretching vibrations of the C–OH groups, bending vibration mode of H–O–H, alkyl C–H stretch, stretching band of Ti–OH, CN asymmetric band stretching, and C=O saturated aldehyde.
134 citations
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TL;DR: In this paper, a sonochemical-assisted method was used to synthesize Fe2O3-TiO2 nanocomposites and the prepared products were characterized by X-ray diffraction pattern, scanning electron microscopy, transmission electron microscopes and Fourier transform infrared spectroscopy.
Abstract: In this work at the first step Fe2O3 nanoparticles were synthesized via a fast microwave method. Then Fe2O3–TiO2 nanocomposites were synthesized by a sonochemical-assisted method. The prepared products were characterized by X-ray diffraction pattern, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. Alternating gradient force magnetometer illustrated super-paramagnetic property of Fe2O3 nanoparticles. The photocatalytic behaviour of Fe2O3–TiO2 nanocomposites was investigated using the degradation of methylene blue under ultraviolet light irradiation. The outcomes confirm that nanocomposites have applicable magnetic and photocatalytic performance. Fe2O3–TiO2 nanostructures were added to cellulose acetate and because of presence of nano-additives properties of polymeric matrix like flame retardancy were increased.
132 citations
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TL;DR: In this article, a chemical precipitation reaction in aqueous ambient involving direct addition of cobalt ion solution to the solution of tungstate reagent was carried out using Taguchi robust design as statistical method.
Abstract: Cobalt tungstate (CoWO4) nanoparticles were synthesized by a chemical precipitation reaction in aqueous ambient involving direct addition of cobalt ion solution to the solution of tungstate reagent. Optimization of the synthesis procedure was carried out using Taguchi robust design as statistical method. In order to controllable, simple and fast synthesis of CoWO4 nanoparticles, effects of some synthesis conditions such as reagents concentrations (i.e., cobalt and tungstate ions), flow rate of cobalt feeding and temperature of the reactor on the particle size of synthesized CoWO4 were investigated by the aid of an orthogonal array (OA9). The results of optimization process showed that CoWO4 nanoparticles could be prepared by controlling the effective parameters and at optimum conditions of synthesis procedure, the size of prepared CoWO4 particles was about 55 nm. Chemical composition and microstructure of the prepared CoWO4 nanoparticles were characterized by means of XRD, SEM, TEM, FT-IR spectroscopy, UV–Vis spectroscopy and fluorescence. The supercapacitive behavior of the CoWO4 electrode has been investigated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The CoWO4 electrode indicates high specific capacitance of 378 F g−1 at scan rate of 2 mV s−1 in 2.0 M H2SO4 electrolyte. Therefore, the prepared electrode could be potential electrode materials for supercapacitors. Moreover, an excellent rate performance, good capacitance retention (~95.5 %) was also observed during the continuous 4000 cycles.
118 citations
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TL;DR: In this paper, a review on the physical properties of tin monoselenide (SnSe) and its device structures in a deeper sense is presented, highlighting the different factors that are limiting the efficiency of SnSe solar cells, and a few suggestions were included to overcome these problems for further improvement of these cells.
Abstract: Currently, selenium (Se)-based compound semiconductors (CISe, CIGSe and CZTSe) are considered as the active materials in the photovoltaic world. However, these materials exhibit couple of issues related to stoichiometry maintenance and scarcity of their constituent elements (In, Ga), which limit their massive production for future energy demands. These issues could be rectified by introducing a non-toxic, inexpensive and earth-abundant binary material. One such material is a tin monoselenide (SnSe), which exhibits a high chemical stability along with attractive physical properties namely, suitable band gap (1.3 eV), high absorption coefficient (105 cm−1) and p-type conductivity. These properties indicate SnSe as a competitive substitute in place of conventional absorbers in thin film solar cells. Despite of its remarkable properties, only a few reports were published on the fabrication of SnSe-based solar cells with poor efficiency (≤1 %). This indicates a need to review on the physical properties of SnSe and its device structures in a deeper sense. In this context, the present review describes the different methods of preparation of SnSe films and their physical properties along with the details of photovoltaic device fabrication. We highlighted the different factors that are limiting the efficiency of SnSe solar cells, and a few suggestions were included to overcome these problems for further improvement of these cells. This review will enrich and stimulate the readers to further investigate the growth of SnSe thin films and their devices, for the development of >20 % efficient SnSe solar cells.
103 citations
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TL;DR: In this paper, the surface morphology of the graphene nanosheet was revealed using AFM studies using Raman fingerprints for single-bilayer and few-layer graphene reflect changes in the electronic structure and electron-phonon interactions and allow unambiguous, high throughput, identification of graphene layers.
Abstract: We report synthesis and structural, chemical and optical properties of graphene nanosheet prepared by facile method. The surface morphology of the graphene nanosheet was revealed using AFM studies. Raman fingerprints for single-bilayer, and few-layer graphene reflect changes in the electronic structure and electron–phonon interactions and allow unambiguous, high throughput, identification of graphene layers. Strong blue shifts were absorbed in the PL spectra that attributed to the quantum confinement effect. FTIR and, XPS results confirm the formation of carbon sheets. The topological features, structural, optical properties of single sheet were closely match with predictions of first principles atomistic modeling. Furthermore facile method of material synthesis described in this article can be used to fabricate innovative 2D nanocrystalline materials with unique properties for broad range of applications.
98 citations
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TL;DR: In this paper, a silver-doped tetragonal phase of cadmium molybdate nanoparticles (Ag°CdMoO4) was successfully synthesized through the sonochemical method.
Abstract: A novel silver-doped tetragonal phase of cadmium molybdate nanoparticles (Ag°–CdMoO4) were successfully synthesized through the sonochemical method. The effect of processing parameters such as the dosage of sucrose and ultrasonic power on the morphology and particle size was investigated. Furthermore, sucrose was applied as a green capping agent. The sample indicated a ferromagnetic behavior, as evidenced by using vibrating sample magnetometer (VSM) at room temperature. The SEM results revealed that the morphology of CdMoO4 nanoparticles is highly dependent on the reaction conditions. Photocatalytic activities of the Ag°–CdMoO4 samples were evaluated by the degradation of methyl orange dye under visible light irradiation. It has been observed that the sample containing 0.5 mol of Ag showed the best photocatalytic activity as compared to other samples. The nanoparticles structure has been elucidated by XRD, SEM, UV–Vis, EDX, VSM, and FTIR.
92 citations
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TL;DR: In this article, the problems and difficulties in the process of study Ag-contained solders and brazing filler metals have been presented, and some suggestions have been put forward which may solve the problem and difficulties mentioned above.
Abstract: Ag is used as a beneficial alloy element in no matter solders or brazing filler metals. Obviously, the addition of Ag has a positive function on melting temperature, wettability, mechanical property and conductivity of filler metals. Therefore, Ag is still widely used in many researches and production in spite of that Ag is very expensive. Respectively, three kind of typical solders (Sn–Ag–Cu, Sn–Zn and Sn–Bi) and brazing filler metals (Ag–Cu–Zn, Cu–P, and Zn–Al) have been chosen for illustration. This article summarizes research status on the studying of Ag-contained solders and brazing filler metals, also analyses influence rules of Ag addition on the change of filler metals’ physical property, microstructure as well as mechanical property. Moreover, the problems and difficulties in the process of study Ag-contained solders and brazing filler metals have been presented. Synchronously, some suggestions have been put forward which may solve the problems and difficulties mentioned above, which provides theory guide for the follow-up study of Ag-contained solders and brazing filler metals, and their prospects are also looked ahead.
91 citations
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TL;DR: In this article, the effect of different chemical approaches on the size, morphology and size distribution of copper vanadate nanostructures in presence of Schiff-base ligand (N,N′-buthylenebis(acetylacetone iminato)dianion) was investigated.
Abstract: The effect of different chemical approaches on the size, morphology and size distribution of copper vanadate nanostructures in presence of Schiff-base ligand (N,N′-buthylenebis(acetylacetone iminato)dianion = acacbn) was investigated. The as-prepared products were characterized using X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectrum, electron dispersive X-ray spectroscopy and ultraviolet–visible spectroscopy. The optical properties and photocatalytic activity of copper vanadate nano and bulk structures were compared by degradation of cationic dye methylene blue in aqueous solution under UV-light irradiation.
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TL;DR: In this paper, a high-performance methane gas sensor based on nickel oxide (NiO)/reduced graphene oxide (rGO) nanocomposite film was reported, which exhibited high response, good repeatability and acceptable selectivity toward methane gas detection.
Abstract: A high-performance methane gas sensor based on nickel oxide (NiO)/reduced graphene oxide (rGO) nanocomposite film was reported in this paper. The hydrothermal synthesized NiO/rGO hybrid nanocomposite was fabricated on a ceramic tube as sensing film. The nanostructures of the NiO/rGO nanocomposite film were characterized by scanning electron microscopy, X-ray diffraction and transmission electron microscope. The methane gas sensing behaviors of the sensor samples were investigated by exposing to various concentration of methane gas at different operating temperature. As a result, the presented sensor exhibited high-response, good repeatability and acceptable selectivity toward methane gas detection. The possible gas sensing mechanism of the proposed sensor was attributed to the Fermi energy band between rGO sheets and NiO nanoparticles. This observed results highlight the hydrothermal synthesized NiO/rGO nanocomposite film can be used as a candidate material for constructing methane sensors, given its simple process, practical usability and cost effectiveness.
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TL;DR: In this article, the authors reported the synthesis of CuS nanoparticles with distinguishable surface plasmonic resonance (SPR) peaks in near infrared region, which is a characteristic SPR peak for CuS nano-composite.
Abstract: In this article we report the synthesis of CuS nanoparticle with distinguishable surface plasmonic resonance (SPR) peaks in near infrared region. For this purpose in situ synthesis (one-step fabrication) has been used to prepare CuS nanoparticles in PMMA polymer matrix at room temperature. The X-ray diffraction spectrum confirms the formation of CuS nanoparticles. The transmittance spectra of nano-composite samples reveal that the samples have a good transparency. The absorption spectra show a broad absorption peak in the wavelength region from 570 to 980 nm which is a characteristic SPR peak for CuS nanoparticle. An increase of refractive index was observed for the samples containing CuS nanoparticles. The linear relationship between the refractive index and volume fraction was observed. The appearance of SPR peak in refractive index spectra was attributed to CuS nanoparticles. Shifting of absorption edge to lower photon energy has been observed for nano-composite samples. The direct energy bandgap of nano-composite samples are reduced compare to pure PMMA polymer. The plot between the direct energy band gap and refractive index reveals that the decrease in bandgap energy is associated with the increase in index of refraction. The increase of optical dielectric constant can be ascribed to the formation of CuS nanoparticles. The low band gap of CuS nanoparticles in the present work reveals their importance for applications in optoelectronic devices.
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TL;DR: In this article, a rod-like CaMoO4 nanostructure was synthesized via free surfactant sonochemical route by utilizing calcium (II) nitrate and ammonium heptamolybdate as the starting materials in an aqueous solution.
Abstract: In this research, we have successfully synthesized rod-like calcium molybdate (CaMoO4) nanostructure via free surfactant sonochemical route by utilizing calcium (II) nitrate and ammonium heptamolybdate as the starting materials in an aqueous solution without any surfactant. The formation of CaMoO4 nanostructure and their structure, shape, and elemental composition were analyzed by means of several techniques including X-ray diffraction, energy dispersive X-ray microanalysis, and scanning electron microscopy. In addition, the photocatalyst activity of as-prepared CaMoO4 nanostructures was evaluated by degradation of methyl orange under ultraviolet light irradiation. Based on the author’s knowledge, it is the first report on photocatalyst activity of CaMoO4 nanostructures. The CaMoO4 nanostructure indicated a ferromagnetic behavior, as evidenced by vibrating sample magnetometer.
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TL;DR: In this paper, the authors investigated the light sensing behavior and also discussed the induced charge transport phenomena through the junction made by aluminium and hydrothermally derived zinc-sulfide (ZnS).
Abstract: In this report we have investigated the light sensing behavior and also discussed the induced charge transport phenomena through the junction made by aluminium and hydrothermally derived zinc-sulfide (ZnS). In this regards the structural, optical and electrical characterization of ZnS was performed well. The optical band gap energy (=3.68 eV) estimated from optical spectra and room temperature conductivity (0.49 × 10−6 S cm−1) measured from current–voltage characteristic explores the inorganic semiconductor behavior of the synthesized material. Depending upon the work function, aluminium (=4.4 eV) was preferred as metal contact to develop a potential barrier within the junction to study the underneath mechanism of charge transport through metal/inorganic-semiconductor interface. Moreover we have fabricated the sandwich structure ITO/ZnS/Al junction to study the effect of incident light on charge transport phenomena and demonstrated the potential applicability of the synthesized material to over crown the research on inorganic nano-semiconductor. The everbound charge transport phenomena within the device was analyzed by thermoionic emission theory. In searching its performance within light sensing electronic device we have deliberated the mobility-lifetime product, diffusion length and density of states (DOS) near Fermi level very aptly.
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TL;DR: In this article, the influence of embedded HgS nanoparticles on the conductivity and dielectric properties of polyvinyl alcohol (PVA) and mercury sulfide (HgS) polymer nanocomposite was investigated.
Abstract: Polyvinyl alcohol (PVA) and mercury sulfide (HgS) polymer nanocomposite were prepared using the solution casting and the in situ chemical reduction of mercury nitrate (Hg(NO3)2) and sodium sulfide (Na2S) in aqueous solutions of PVA as capping for different molar content of Hg(NO3)2 and Na2S. The nanocomposites films were characterized by Fourier transform infrared, X-ray diffraction (XRD), and scanning electron microscopy. The XRD results for the nanoparticles revealed the hexagonal structure of the HgS, (α-phase). The influence of embedded HgS nanoparticles on the conductivity and dielectric properties of PVA films are investigated, over the frequency range 1 kHz–1 MHz, and the temperature range 30–110 °C. The variation of ac-conductivity with a frequency of the films follows Jonscher’s universal power law and found to be increased with increasing temperature, frequency and nanoparticle content. The variation of frequency exponent (s) indicated that the conduction mechanism was correlated barrier hopping model. The dielectric constant (ɛ′), and dielectric loss (ɛ″) was found to decrease with increasing frequency, but increase with increasing temperature and HgS nanoparticles content. The dc-conductivity (σ
dc
) increase with increase of HgS concentration, and follows Arrhenius behavior in the investigated temperature region.
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TL;DR: In this article, high photocatalytically active Nd2Sn2O7-SnO2 nanocomposites have been prepared through a simple salt-assisted combustion approach.
Abstract: Highly photocatalytically active Nd2Sn2O7–SnO2 nanocomposites have been prepared through a simple salt-assisted combustion approach. NaCl as dispersing agent and different amino acids as fuel and capping agent have been utilized to prepare Nd2Sn2O7–SnO2 nanocomposites for the first time. The as-obtained Nd2Sn2O7–SnO2 nanocomposites have been analyzed by TEM, FT-IR, UV–Vis, EDX, FESEM, and XRD. According to the FESEM and XRD investigations of the as-synthesized nanocomposites, it was found that grain size, shape and purity of the nanocomposites are controlled by setting the factors such as the tin source and amino acid type. Additionally, the photocatalytic behaviour of Nd2Sn2O7–SnO2 nanocomposites was evaluated by photodegradation of methyl orange dye.
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TL;DR: In this paper, an attempt is made to synthesize cobalt tungstate (CoWO4) nanoparticles via a large-scale and facile precipitation method with the aid of cobalt (II) nitrate and sodium tung state dihydrate in an aqueous solution.
Abstract: In the current study, an attempt is made to synthesize cobalt tungstate (CoWO4) nanoparticles via a large-scale and facile precipitation method with the aid of cobalt (II) nitrate and sodium tungstate dihydrate in an aqueous solution. Besides, three surfactant agents such as sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, and ethylene diamine tetra acetic acid were used to investigate their effects on the morphology and particle size of CoWO4 nanoparticles. XRD, SEM, EDS, and UV–Vis spectroscopy were employed to characterize structural, morphological, and optical properties of CoWO4 nanoparticles. According to the vibrating sample magnetometer result, CoWO4 nanoparticles indicated a paramagnetic behavior at room temperature. In addition, methyl orange was chosen as a dye water pollution to evaluate its degradation by as-synthesize copper tungstate under ultraviolet light irradiation. Furthermore, the photocatalysis results reveal that the maximum decolorization of 70 % for methyl orange occurred with CoWO4 nanoparticles in 70 min under ultraviolet (UV) light irradiation.
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TL;DR: In this paper, the effect of pH on photocatalytic degradation of Rose Bengal, Methylene blue, and Bromocresol green dyes was investigated with different pH values.
Abstract: In this study, ZnO nanoparticles were fabricated by co-precipitation method. The synthesized nanoparticles possessed monodispersity with the average size 20–30 nm. Since the industrial effluents may not be at neutral pH, the effect of pH on the rate of degradation is important and need to be considered. In order to investigate the effect of pH on ZnO nanoparticles photocatalytic activity, the photocatalytic degradation of Rose Bengal, Methylene blue, and Bromocresol green dyes, was studied with different pH values. It was observed that the adsorption of the dyes onto ZnO nanoparticles surface is strongly dependent on the pH of the solution which plays an important role in photocatalytic degradation.
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TL;DR: In this article, a facile and cost-effective catalysts have been developed on platinum nanoparticles (PtNPs) supported on nitrogen and sulfur-doped reduced graphene oxide (NSrGO).
Abstract: A fuel cell is an electrochemical cell that converts a source fuel into an electrical current. It generates electricity inside a cell through reactions between a fuel and an oxidant, triggered in the presence of an electrolyte. Fuel cells have been attracting more and more attention in recent decades due to high-energy demands, fossil fuel depletions and environmental pollution throughout world. In this study, a facile and cost-effective catalysts have been developed on platinum nanoparticles (PtNPs) supported on nitrogen and sulfur-doped reduced graphene oxide (NSrGO). The successful synthesis of nanomaterials and the prepared glassy carbon electrode (GCE) surfaces were confirmed by transmission electron microscope (TEM), X-ray photo electron spectroscopy (XPS), scanning electron microscope (SEM) and electrochemical impedance spectroscopy (EIS). According to TEM images, the average particle sizes of PtNPs were found to be approximately 15–20 nm. The effective surface areas (ESA) of NSrGO/GCE and PtNPs/NSrGO/GCE were calculated to be 148 and 469 cm2/mg, respectively. The PtNPs/NSrGO/GCE also exhibited a higher peak current for methanol oxidation than those of comparable GCE and NSrGO/GCE, providing evidence for its higher electro-catalytic activity.
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TL;DR: In this paper, a precipitation method was used in order to synthesize AgO nanostructures with the aid of silver nitrate as the starting reagent in an aqueous solution.
Abstract: In this research, a precipitation method was used in order to synthesize AgO nanostructures with the aid of silver nitrate as the starting reagent in an aqueous solution. To examine the effect of different surfactants such as glucose, sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, and cetyltrimethylammonium bromide on the morphology and particle size of final products several tests were performed. The structural, morphological, and optical properties of as-obtained products were characterized by techniques such as Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and ultraviolet–visible spectroscopy. Furthermore, the hysteresis loop measured at room temperature shows a ferromagnetic behavior of the AgO nanostructures. To evaluate the catalytic properties of nanocrystalline silver oxide (AgO), the photocatalytic degradation of rhodamine-B under visible light irradiation was carried out.
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TL;DR: In this article, pure barium stannate (BaSnO3) nanostructures were prepared via a new facile surfactant-free coprecipitation-calcination route by employing Ba(Sal)2 (Sal = salicylidene) and SnCl2·2H2O as precursors.
Abstract: Pure barium stannate (BaSnO3) nanostructures were prepared via a new facile surfactant-free coprecipitation-calcination route by employing Ba(Sal)2 (Sal = salicylidene) and SnCl2·2H2O as precursors. Ba(Sal)2 was employed as precursor to synthesize BaSnO3 nanostructures for the first time. The as-obtained BaSnO3 nanostructures were analyzed by UV–vis diffuse reflectance spectroscopy, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray microanalysis, transmission electron microscopy, and X-ray diffraction. Based on the morphological investigations of the as-prepared samples, it was found that the particle size and shape of the BaSnO3 depended on the reaction temperature, precipitator and surfactant. BaSnO3 nanostructures with various shapes and particle sizes were successfully prepared. Furthermore, the photocatalytic properties of as-synthesized BaSnO3 were evaluated by degradation of eriochrome black T (anionic dye) as water contaminant.
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TL;DR: In this article, the photo-catalytic water splitting was used as a model reaction to evaluate the photo catalytic activity of the obtained cobalt-modified tungsten-titania nanotubes.
Abstract: Cobalt modified tungsten–titania nanotubes (Co/WTNs) with different amounts of cobalt were prepared by two methods; photo-assisted deposition and one-step electrochemical anodizing method. The morphology, crystallinity, elemental composition and light absorption capability of samples were characterized by field emission scanning electron microscope, X-ray diffraction, energy dispersive X-ray spectrometer and ultraviolet–visible spectroscopy methods. All cobalt loaded samples show a red shift relative to the unloaded samples. The photo-catalytic water splitting was used as a model reaction to evaluate the photo-catalytic activity of the obtained samples. The photo-catalytic performance was examined under xenon lamp irradiation in 1 M NaOH electrolyte. All cobalt modified samples showed photo-catalytic properties better than that for the bare WTNs and bare TiO2 samples. The total amount of H2 evolved on the Co/WTNs2 sample was 1.9 times higher than that on the bare TiO2 sample. The catalysts prepared in this study exhibit industrially relevant interests due to the low cost and high photocatalytic activity. These new photoanodes are highly promising photoanodes for photo-catalytic hydrogen production.
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TL;DR: In this article, the first time that cadmium tungstate was synthesized by ultrasonic method, the structural, morphological, and optical properties of as-obtained products were characterized by X-ray diffraction, Scanning electron microscopy, Fourier transform infrared spectroscopy, energy dispersive Xray microanalysis (EDS), and ultraviolet-visible spectrograph.
Abstract: Cadmium tungstate (CdWO4) nanoparticles were synthesized via a sonochemical method based on the reaction between cadmium(II) nitrate hexahydrate and sodium tungstate dihydrate in an aqueous solution. To the best of authors’ knowledge, it is the first time that cadmium tungstate was synthesized by ultrasonic method. The structural, morphological, and optical properties of as-obtained products were characterized by X-ray diffraction, Scanning electron microscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray microanalysis (EDS), and ultraviolet–visible spectroscopy. The as-synthesized cadmium tungstate indicated a ferromagnetic behavior which evidenced by using vibrating sample magnetometer at room temperature. To evaluate the photocatalysts properties of nanocrystalline cadmium tungstate, the photocatalytic degradation of methyl orange under ultraviolet light irradiation was carried out.
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TL;DR: In this paper, the ionic conductivity and dielectric properties of PVA/PVP/Li2CO3 polymer blend electrolyte films were investigated using an impedance spectroscopy.
Abstract: New solid polymer blend electrolyte films based on biodegradable polymer blend comprising of polyvinyl alcohol (PVA) and poly (N-vinyl pyrrolidone) (PVP) doped with different wt% of lithium carbonate (Li2CO3) salt have been prepared by solution casting method. The resulting PVA/PVP/Li2CO3 polymer blend electrolyte films have been characterized by various analytical techniques such as FTIR, UV–vis, XRD, TGA, polarized optical microscopy and scanning electron microscopy. The FTIR and XRD analysis confirmed the complex formation between PVA/PVP blend and Li2CO3 salt. The ionic conductivity and the dielectric properties of PVA/PVP/Li2CO3 polymer blend electrolyte films were investigated using an impedance spectroscopy. It was observed that the ionic conductivity of PVA/PVP/Li2CO3 electrolyte system increases as a function of Li2CO3 concentration. The highest ionic conductivity was found to be 1.15 × 10−5 S cm−1 for polymer blend electrolyte with 20 wt% Li2CO3 content. On the other hand, the dielectric results revealed the non-Debye type of behaviour. The dielectric constant values indicate a strong dielectric dispersion in the studied frequency range which increases as the Li2CO3 content increases. The dielectric constant as high as 1200 (e = 1201.57, 50 Hz, 150 °C) and the dielectric loss well below 4 (tan δ = 3.94, 50 Hz, 150 °C) were obtained for polymer blend electrolytes with 25 wt% Li2CO3 salt. Thus, the results obtained in the present study suggest that the PVA/PVP/Li2CO3 polymer blend electrolyte system seems to be a promising candidate for solid state battery applications.
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TL;DR: In this article, an organo-modified 2D montmorillonite (OMMt) nanoparticles were synthesized and characterized using a dielectric strength tester, concept 40 impedance analyzer, scanning electron microscope (SEM), and thermogravimetric analysis techniques.
Abstract: Thermostable nanocomposites based on interpenetrating polymer network bismaleimide/cyanate ester (BMI/CE) copolymer, derived from bisphenol A dicyanate, 4,4′-bismaleimidodiphenyl methane, and doped by 1–5 wt% organo-modified 2D montmorillonite (OMMt) nanoparticles were synthesized and characterized using a dielectric strength tester, concept 40 impedance analyzer, scanning electron microscope (SEM), dynamic mechanical analysis, and thermogravimetric analysis techniques. OMMt improves the dispersibility, alignment and interfacial strength of these nanocomposites, the electrical conductivity increase with increasing OMMt loading, and a suitable addition of OMMt can enhance the mechanical properties and dielectric property of BMI/CE copolymer. SEM analysis shows distinct characteristics of a ductile fracture of the blends. In addition, the OMMt/BMI/CE nanocomposites have a better thermal stability and a higher thermal conductivity compared to those of BMI/CE resin with the increasing of OMMt content. All of these changes in properties are closely correlated with the OMMt/BMI/CE nanocomposites, which could form an interaction interface structure in the system.
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TL;DR: In this article, the authors presented the preparation and investigations of zirconium oxide (ZrO2) nanoparticles that were synthesized by hydrothermal method and the products were characterized by means of powder X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscope (TEM), UV-absorption spectroscopy and photoluminescence (PL) spectra.
Abstract: The paper presents the preparation and investigations of zirconium oxide (ZrO2) nanoparticles that were synthesized by hydrothermal method. The products were characterized by means of powder X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-absorption spectroscopy and photoluminescence (PL) spectroscopy. The crystal structure was determined using X-ray diffraction. The morphology and the particle size were studied using (SEM) and (TEM). The spherical shaped particles were confirmed through the SEM analysis. The transmission electron microscopic analysis confirmed the formation of the nanoparticles with the particle size. The FT-IR and Raman spectrum ascertained the strong presence of ZrO2 nanoparticles. The optical properties were obtained from UV–visible absorption spectrum and also PL emission spectrum. The dielectric constant and the dielectric loss were measured as a function of frequency and temperature.
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TL;DR: In this article, the effects of Ni nanoparticles on the formation of intermetallic compound (IMC) layers and mechanical properties of low melting temperature Sn-58Bi (wt%) based solders on copper (Cu) substrate were investigated.
Abstract: This paper investigates the effects of Ni nanoparticles on the formation of intermetallic compound (IMC) layers and mechanical properties of low melting temperature Sn–58Bi (wt%) based solders on copper (Cu) substrate. At the initial reaction for the plain Sn–Bi solder/Cu substrate system, an island-shaped Cu6Sn5 IMC layer was found to adhere at the substrate surface. A very thin Cu3Sn IMC layer was also observed between the Cu6Sn5 IMC layer and Cu substrate as the reaction time increased. However, in the composite solders doped with Ni nanoparticles, a scallop-shaped ternary (Cu, Ni)–Sn IMC layer appeared at the interface without Cu3Sn IMC layer. In the solder ball region, the Bi phase with bright contrast was homogeneously distributed in the β-Sn matrix. After adding the Ni nanoparticles, an additional very fine Sn–Ni IMC particle was found to have been distributed in the β-Sn matrix. The IMC layer thicknesses were increased with the reaction time and temperature. However, the IMC growth behavior of composite solder was slower than that of the plain solder system. Furthermore, the mechanical properties of the composite solder exhibited higher values than that of the plain Sn–Bi solder due to the strengthening effect of fine Sn–Ni IMC particles.
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TL;DR: In this paper, pure and Ni-doped ZnO nanoparticles were successfully synthesized by using the wet chemical precipitation method, which revealed the formation of single phase hexagonal wurtzite structure, without formation of any secondary and other impurity phases.
Abstract: In this study, pure ZnO and Ni doped ZnO nanoparticles were successfully synthesized by using the wet chemical precipitation method. Pure and Ni doped ZnO nanoparticles samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS), UV–visible (UV–Vis) and FTIR spectroscopy. The XRD investigation of pure and Ni-doped ZnO nanoparticles samples reveal and confirm the formation of single phase hexagonal wurtzite structure, without formation of any secondary and other impurity phases. XRD results further reveals the shifting of characteristics peak toward higher 2θ (theta) angle with Ni doping. This shifting of the XRD peaks toward higher angle clearly indicates that Ni ions are effectively incorporated in the ZnO lattice. Surface morphology of pure and Ni doped ZnO nanoparticles samples was performed by using the SEM confirms the formation of spherical nanocrystallites with fine and clear defined boundaries. EDS spectroscopy indicates the substitution of dopant Ni2+ effectively in lattice site of Zn2+ as evident from XRD result also. The carriers i.e. donors confined on the Ni sites were confirmed from the micro Raman spectroscopy. Optical property of Ni-doped samples is confirmed by using the UV–Vis absorption which showed blue shift in absorption edge as compared to undoped ZnO nanoparticles. Undoped and Ni-doped ZnO nanoparticles exhibit considerable changes in the M–H loop, specifically the diamagnetic response changed into ferromagnetic character for Ni doped samples in VSM investigation. The antibacterial activities of the Nickel doped zinc oxide were studied against Gram-negative (Shigella dysenteriae, Vibrio cholerae, and E. coli) via using agar well diffusion technique. Further, these Ni doped nanoparticles were then applied as antibacterial agent to control the microorganisms or bacterial growth. Ni-doping on zinc oxide and exposure of sunlight enhanced the antibacterial activity against bacterial pathogens which isolate at 40–45 μg concentration. Interestingly in this study, most effective antibacterial results were obtained against the water related bacteria such as E. coli and V. cholerae for Ni-doped ZnO NPs.
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TL;DR: In this paper, structural, electronic and optical properties of the recently synthesized bismuth based Zr2(Al1−x.............. Bi�Ⴗ ₷ ₷ ǫ (Zr2BiC) MAX phases were investigated, and it was revealed that the inclusion of Bi in the A site causes an increase of lattice constant a, whereas the lattice constants c decreases with increasing Bi content x up to 0.58.
Abstract: In this study we investigate the structural, electronic and optical properties of the recently synthesized bismuth based Zr2(Al1−x
Bi
x
)C MAX phases. It is revealed that the inclusion of Bi in the A site causes an increase of lattice constant a, whereas the lattice constant c decreases with increasing Bi content x up to 0.58. The c values are more influenced than the a values while Al is substituted by Bi, which implies that the c value is more dependent on the M–A bonds than the M–X bonds. The calculated band structures imply that the electrical conductivity along the c direction should be small enough compared to that in the ab plane. The low density of states (DOS) around the Fermi level indicate that Zr2(Al1−x
Bi
x
)C should be stable in view of the electronic structure. The total DOS at the Fermi level increases almost linearly with the increase of the Bi content x between 0.25 and 0.75. The Mulliken atomic population calculations indicate that the Zr–C bonds are more covalent in Zr2BiC than that of Zr2AlC. The calculated Vickers hardness of Zr2AlC and Zr2BiC are calculated to be 5.96 and 1.94 GPa, respectively, implying that Zr2BiC is relatively soft and easily machinable compared to Zr2AlC. The calculated optical functions (dielectric constants, refractive index, extinction coefficient, absorption coefficient, loss function, reflectivity, and optical conductivity) show the dependence on the polarization directions.