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1.
Mohd Zubair Ansari Mohd Faraz Sandeep Munjal Vikram Kumar Neeraj Khare 《Advanced Powder Technology》2017,28(9):2402-2409
Highly dispersible, uniform size (~7 nm) single-phase Cu2ZnSnS4 nanoparticles have been synthesized by hydrothermal method using non-toxic surfactant (oleic acid). High resolution transmission electron microscopy image indicates good crystallinity of the Cu2ZnSnS4 nanoparticles with the growth along (1 1 2) plane. X-ray photoelectron spectroscopy analyses suggested that the formation of with Cu, Zn, and Sn in +1, +2 and +4 oxidation states. The optical absorption spectrum of Cu2ZnSnS4 nanoparticles exhibits an absorption in the visible region and its optical band gap was found to be ~1.72 eV, which could be much more appropriate for photocatalytic application under visible light irradiation. These Cu2ZnSnS4 nanoparticles have been shown high photocatalytic degradation activity of methylene blue (MB) dye in the presence of visible light irradiation. The rate constant (k) value of Cu2ZnSnS4 nanoparticles is found to be 0.0144 min?1. We have discussed the mechanism of dye degradation process that drives the photocatalytic degradation process. The reusability of the Cu2ZnSnS4 nanoparticles for the dye degradation is also demonstrated. 相似文献
2.
Jiseung Ryu 《Advanced Powder Technology》2017,28(1):299-303
PrBaCo1.9Cu0.1O5+δ (PBCCO) nanopowders were synthesized by an EDTA-citrate complexing process using water and ethanol as solvents, and their structures and electrochemical properties were characterized. PBCCO precursor gels were highly oxidized at 450 °C, using either water (PBCCO-W) or ethanol (PBCCO-E) as the solvent. PBCCO powders calcined at 450 °C had a second phase, while those calcined at 850 °C for 4 h were obtained as single phase PBCCO with a layered perovskite structure in the P4mm space group. PBCCO-E primary particles were approximately 5–10 nm in size and were well-dispersed compared with those of the PBCCO-W powder. We hypothesized that the enhanced dispersibility of the PBCCO-E powder was caused by a decrease in bridging hydrogen bonds on the chelate surface, which prevents chelate agglomeration in sol state. It causes the larger specific surface area of PBCCO-E powders and thus a lower polarization resistance (Rp) than that of PBCCO-W powders at the measured temperature. The Rp value of PBCCO-E powder was 0.041 Ω cm2 at 750 °C, which is about 1.5 times lower than that of PBCCO-W at the same temperature. 相似文献
3.
A simple and rapid method has been developed to synthesize cuprous selenide (Cu2Se) nanoparticles by the reaction of selenium nanoparticles sol with copper sulfate solution containing ascorbic acid at room temperature. Cu2Se nanoparticles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive X-ray analysis (EDX). The results indicated that Cu2Se nanoparticles were cubic crystal structure and spherical with the diameter about 75 nm. The ultraviolet–visible absorption spectrum (UV–vis) and cyclic voltammetry of Cu2Se nanoparticles were also investigated. The optical band gap energy of Cu2Se nanoparticles was 1.94 eV. On the basis of a series of experiments and characterizations, the formation mechanism of Cu2Se nanoparticles was discussed. 相似文献
4.
Reena Okram Ganngam Phaomei N. Rajmuhon Singh 《Materials Science and Engineering: B》2013,178(7):409-416
Well-dispersed Dy3+ and Sm3+ doped LaVO4 nanoparticles have been synthesized at a relatively low temperature of 140 °C in ethylene glycol (EG), water, N,N′-dimethyl formamide (DMF) and mixed solvents. The samples prepared in water show mixed tetragonal and monoclinic phase where tetragonal planes are found to be dominated over the monoclinic planes. However, the samples prepared in EG and DMF show monoclinic phase. Due to the phase transformation of the samples prepared in water the luminescence intensity of these samples is highly enhanced than that of the samples prepared in EG and DMF. The mixed phase of the samples prepared in water transformed to pure monoclinic phase when heated at 900 °C. The luminescence intensity of Dy3+ and Sm3+ doped LaVO4 prepared in EG are also enhanced when large divalent Ba2+ ions is used as co-activator. The optimum concentration for Ba2+ ions was found to be 1 at.% in both Dy3+ and Sm3+ doped systems. The prepared nanoparticles are subsequently dispersed in methanol and incorporated in polymer films of PVA which showed the characteristic emissions of Dy3+ and Sm3+ when irradiated under UV light. 相似文献
5.
Xiran Wang Shizhong Wei Liujie Xu Jiwen Li Xiuqing Li Kangning Shan 《Advanced Powder Technology》2018,29(6):1323-1330
A novel chemical co-precipitation was used to produce W-70%Cu nanocomposite powders with coating structure. The precursors consisting of CuC2O4·xH2O and WO3·2H2O were first synthesized using copper nitrate, ammonium metatungstate(AMT) and oxalic acid as the raw materials at 80?°C for 1.5?h when the concentrations of the reactants were 0.8?mol/L and the hydrogen ion concentration was 1.2?mol/L. The precursors were calcined to produce the powders with different phase components and microstructure at various temperatures. The CuWO4 and CuO nano-powders were obtained at 300?°C, which is colder than the traditional reaction temperature (1000?°C) of CuO?+?WO3 = CuWO4. However, the cubic Cu2O and Cu2WO4 could be formed when the calcining temperature was 600?°C. The hydrogen reduction results show that the calcined powder is reduced to obtain W-Cu composite powder at 750?°C and 800?°C. In reduction process, volatile WO2(OH)2 through chemical vapor transport(CVT) continuously spreads to the copper surface and is reduced to form W and the coated particle is eventually formed. This particle is Cu particle coated by W phase and the interface between W and Cu phases is semi-coherent. It is found that the average particle size of the reduced powder is 30–50?nm observed by TEM images. 相似文献
6.
The synthesis of magnetic NiFe2O4@AlMCM-41-Cu2O core-shell as a new class of visible light driven photocatalyst was suggested. The magnetic NiFe2O4 core was prepared by solvothermal method. The intermediate AlMCM-41 shell was prepared by the method of liquid crystal templating mechanism and subsequently cuprous oxide (Cu2O) nanoparticles (NPs) were synthesized in NiFe2O4@AlMCM-41core-shell via colloidal chemistry approach. The properties of prepared magnetic core-shell were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), nitrogen adsorption–desorption measurement and vibration sample magnetometer (VSM). Based on EDX results, the weight percentage (wt%) of NiFe2O4 core, MCM-41 shell and Cu2O NPs were calculated to be 68.89, 30.55 and 0.56%, respectively. It consisted of mesoporous structure with a surface area of 687.00 m2 g?1, an average pore size of 2.95 nm and possessed excellent magnetic properties of 4.74 emu g?1. The TEM results indicated that the NiFe2O4 as core were regular spheres with diameter of 68 nm, and the average thickness of AlMCM-41 shells was ~35 nm. The particles size of Cu2O incorporated in core-shell was less than 5 nm. The photocatalytic activity was evaluated under visible light irradiation using the removal of methylene blue (MB) dye as a model reaction. The removal rate of MB achieved up to 90% after 60 min under visible light irradiation, and the NiFe2O4@AlMCM-41-Cu2O can be recycled and reused. 相似文献
7.
Shuriken-like nickel nanoparticles were successfully synthesized by a thermal decomposition method at 200 °C with Nickel(II) acetylacetonate (Ni(acac)2) as the precursor and oleylamine (OAm) as the solvent and reductant, respectively. The phase structures, morphologies and sizes, and magnetic properties of the as-synthesized nickel products were characterized in detail by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and vibrating sample magnetometer (VSM). Some key reaction parameters, such as the reaction time, reaction temperature and surfactants, have important influence on the morphology of the final products. XRD pattern indicated that the products are well-crystallized face-centered cubic (fcc) nickel phase. SEM images demonstrated that the nickel nanoparticles are shuriken-like morphology with average size around 150 nm. The mechanism of shuriken-like Ni nanoparticles (NPs) is proposed. The magnetic hysteresis loops of shuriken-like and spherical nickel products illustrated the ferromagnetic nature at 300 K, indicating its potential applications in magnetic storage. 相似文献
8.
Ming-Guo Ma Shu-Ming Li Ning Jia Jie-Fang Zhu Run-Cang Sun Ying-Jie Zhu 《Materials Letters》2011,65(19-20):3069-3071
The Ag/calcium silicate nanocomposite with core-shell nanostructure has been successfully synthesized using Ag solution, Ca(NO3)2·4H2O and Na2SiO3·9H2O in ethanol/water mixed solvents at room temperature for 48 h. Ag solution was previously prepared by microwave-assisted method in ethylene glycol (EG) at 150 °C for 10 min. The nanocomposites consisted of Ag core and an amorphous calcium silicate shell. The XRD and EDS results confirmed that the product was the Ag/calcium silicate nanocomposite. The TEM micrographs indicated that the Ag/calcium silicate nanocomposite was core-shell nanoparticles. The effects of Ca(NO3)2·4H2O and Na2SiO3·9H2O concentration on the shells of Ag/calcium silicate nanocomposite were investigated. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and energy-dispersive X-ray spectra (EDS). This method is simple, fast and may be extended to the synthesis of the other kinds of core-shell nanocomposites. 相似文献
9.
Wenle Ma Yongmei Feng Li Wang Yanhong Li Min Shi Hongtao Cui 《Advanced Powder Technology》2017,28(10):2642-2647
In this work, we report the preparation of Co2(OH)3Cl nanoparticles with average size of ~20 nm and well-defined cubic shape at room temperature by an epoxide precipitation route. It was found that the as-prepared Co2(OH)3Cl nanoparticles could be used as a promising new electrode material for application in redox supercapacitors due to its high electrochemical performance. It presented superior specific capacitance of 783 F g?1 at low current density of 2.8 A g?1, while it had a high value of 604 F g?1 at high current density of 56.6 A g?1, proving its excellent high rate performance. Its 75% capacitance retention after 10,000 cycles of charge–discharge demonstrated its long-life span. According to characterization results, the possible mechanism for the electrochemical process that Co2(OH)3Cl nanoparticles underwent was proposed as a process of Co2(OH)3Cl → β-Co(OH)2 → CoOOH ? Co3O4. 相似文献
10.
Pure CuInSe2 nanoparticles have been successfully synthesized via a solution method in the solvent of oleylamine. Anhydrous InCl3, CuCl, and Se powder were used as the starting materials. The CuInSe2 samples were characterized by XRD, TEM, and XPS techniques. It was found that tetragonal chalcopyrite structured CuInSe2 nanoparticles were obtained with temperature above 230 °C. Sample prepared at 200 °C possesses triangular morphology and a minute amount of In2Se3 coexists as intermediate. CuInSe2 nanoparticles with size of 20.2 ± 0.4 nm were prepared at 230 °C and the narrow size distribution was ascribed to the employment of hot injection, which was better for homogeneous nucleation. Stable “ink” can be formed when the as-synthesized CuInSe2 nanoparticles were dispersed in organic solvents such as hexane and tolune, and such “ink” might have a practical application in CuInSe2-based solar cells. 相似文献
11.
Xiaojiong Chen Panfeng Wang Jingcai Xu Yanbing Han Hongxiao Jin Dingfeng Jin Xiaoling Peng Bo Hong Jing Li Yanting Yang Hongliang Ge Xinqing Wang 《Advanced Powder Technology》2017,28(9):2087-2093
Magnetic NiFe2O4/SBA-15 nanocomposites were synthesized by a facile impregnation method, and NiFe2O4 nanoparticles presented spinel phase structure and existed in the mesopores of SBA-15. Partial mesopores were blocked by NiFe2O4 nanoparticles and micropores formed, which the capillarity of micropores played a decisive role for methylene blue (MB) adsorption. The saturation magnetization increased from 2.34 emu g?1 to 10.03 emu g?1 with the NiFe2O4 content, while the specific surface area decreased from 552.18 m2 g?1 to 260.40 m2 g?1 and pore volume decreased from 1.13 cm3 g?1 to 0.49 cm3 g?1. MB adsorption could be improved by optimizing the NiFe2O4 content of the nanocomposites. MB could be adsorbed completely in 60 min with the optimum nanocomposites and could be separated easily from water by magnetic separation technique. 相似文献
12.
《材料与设计》2015
ZnO nanoparticles were synthesized solvothermally in various diols (ethylene glycol, di(ethylene glycol), tetra(ethylene glycol), 1,2-propanediol, 1,4-butanediol), using basic zinc carbonate (2ZnCO3·3Zn(OH)2) as a precursor for the first time. Since ZnCO3 was sparingly soluble in diols the transformation reaction proceeded at a low reaction rate. Ethylene glycol was found as the most suitable medium among five diols studied yielding the smallest ZnO particles (~ 55 nm) and short reaction time, tr (2 h). Diols with shorter chain length produced smaller ZnO particles. p-Toluene sulfonic acid (p-TSA) acted as a catalyst and reduced tr from 8 h to 2 h in concentration of 0.02 M. Optimum reaction conditions for the synthesis in ethylene glycol were 185 °C and 2 h. At higher p-TSA concentrations (0.04–0.08 M) the size of ZnO particles was reduced from 500–800 nm to 50–100 nm and crystallite size to 25–30 nm. Benzene sulfonic acid (BSA) and inorganic bases (LiOH, NaOH, and KOH) also showed catalytic activities. Raman and photoluminescence spectroscopies revealed high concentration of defects on ZnO surface causing the emission of visible light and giving this type of ZnO higher potential in various (opto)-electronic application in comparison to Zn(II) acetate based ZnO. 相似文献
13.
《Materials Research Bulletin》2013,48(4):1347-1351
This paper describes a novel synthesis method of stabilizer-free Pt/TiO2 composite nanoparticles using electron beam irradiation. The chemical compositions were analyzed by inductively coupled plasma-atomic emission spectroscopy. The microstructures of the samples were observed by using transmission electron microscope. Pt nanoparticles with the sizes of 2–4 nm were deposited on TiO2 without any use of stabilizers. The concentrations of Pt ions and 2-propanol notably affected the size and shape of Pt nanoparticles. Their reactions of preferential CO oxidation were measured in temperature region from 60 to 140 °C. The Pt/TiO2 catalyst with spherical Pt nanoparticles exhibited a 67% of CO conversion rate and 100% of selectivity at a low temperature of 60 °C. 相似文献
14.
Heguo Zhu Xiaodong Sun Zhuli Yu Jiewen Huang Jianliang Li Zonghan Xie 《Advanced Powder Technology》2017,28(10):2572-2580
Reaction mechanisms, microstructures and tensile properties of the aluminum matrix composites made from Al-SiO2-Mg system were investigated. When the temperature increased from room temperature to around 761 K, Mg dissolved into Al to form Mg-Al alloy. As the temperature increased to about 850 K, the remaining Mg reacted with SiO2 to form MgO, Mg2Si and Si as expressed in step reaction I: 6Mg + 2SiO2 → 4MgO + Mg2Si + Si. Finally, with a further increase in temperature, the remaining SiO2 reacted with Al to produce Al2O3 and Si, while MgO reacted with Al2O3 to form MgAl2O4 as expressed in step reaction II: 4Al + 3SiO2 + 2MgO → 2MgAl2O4 + 3Si. The Si also dissolved into matrix Al to form Al-Si alloy. Accordingly, its reaction process consisted of two steps and their apparent activation energies were 218 kJ/mol and 192 kJ/mol, respectively. As compared to the composites prepared by Al-SiO2 system, its density increased from 2.4 to 2.6 g/cm3, and its tensile strength and elongation increased from 165 MPa and 3.95% to 187 MPa and 7.18%, respectively. 相似文献
15.
J. Grace Nirmala S. Akila R.T. Narendhirakannan Suvro Chatterjee 《Advanced Powder Technology》2017,28(4):1170-1184
Gold nanoparticles (AuNPs) are considered beneficial in the field of biomedicine and in the development of therapeutic nanomedicine products. In the present study, Vitis vinifera. L (grapes) peel polyphenols were utilized as reducing and stabilizing agents for the biosynthesis of gold nanoparticles, and their cytotoxicity and apoptotic effects were assessed. The synthesized gold nanoparticles were characterized using UV-Visible spectroscopy, Transmission electron microscopy (TEM), X-ray diffraction (XRD), Particle size distribution, Fourier transform infrared spectroscopy (FTIR) and zeta potential analysis. TEM analysis confirmed that the nanoparticles were spherical with ~20–40 nm in size. Particle size distribution revealed ~50 ± 5 nm nanoparticles and FTIR confirmed the presence of polyphenols capped onto the peel gold nanoparticles. The V. vinifera peel gold nanoparticles were studied for their antiproliferative activities and induction of apoptosis at the inhibitory concentration (IC50) of 23.6 µM. A431 cell lines incubated with V. vinifera peel gold nanoparticles for 24 h exhibited cytotoxicity activity mediated by increased reactive oxygen species (ROS) production, apoptotic morphological changes and loss of membrane potential significantly (p < 0.01). Thus, the cytotoxicity of the gold nanoparticles could be attributed to the synergistic effects of the phenolic moieties of the V. vinifera peels and the efficiency of the bioconjugated gold nanoparticles causing apoptosis and secondary necrosis. 相似文献
16.
J. Manikantan H.B. Ramalingam B. Chandar Shekar B. Murugan R. Ranjith Kumar J. Sai Santhoshi 《Advanced Powder Technology》2017,28(7):1636-1646
HfO2 nanoparticles (HfO2 NPs) with different precursors (NaOH, H2O, ethanol) were synthesized by a simple co-precipitation method. FTIR and EDX spectroscopy analysis shows the Stoichiometries composition of HfO2 NPs. X-ray diffraction pattern analysis revealed that the as prepared and calcined HfO2 NPs are respectively amorphous and polycrystalline nature. TEM analysis confirms that the morphology of the calcined HfO2 NPs is spherical in shape with less agglomeration. The crystallite size was evaluated to be 51 nm, 37 nm and 30 nm respectively, for the precursors NaOH, H2O and ethanol used for HfO2 NPs. SEM analysis shows spherical, rock and sponge like surface morphology respectively, for the precursors NaOH, H2O and ethanol used for HfO2 NPs. UV–visible spectroscopy analysis revealed that the optical band gap energy of NaOH, H2O and ethanol precursors used HfO2 NPs were respectively 5.50 eV, 5.52 eV and 5.50 eV. The observed optical properties indicated the feasibility of utilizing these NPs as anti reflection layers in solar cells and for the construction of poultry farms to save energy. The estimated dielectric constant value indicated that these NPs could be used to prepare dielectric layers in thin film transistor. 相似文献
17.
In this research ZnO and Zn1?x AlxO (x = 1, 3, 5, 7% mol) nanoparticles were synthesized by sol-gel method. The effect of Al concentration on the structure, morphology, absorption spectra and photocatalytic properties investigated by using X-ray, TEM, EDS and UV–Vis spectrophotometer approaches. Hexagonal, spherical and rod-like structure was achieved as the dominant structure for undoped nanoparticles, low and high concentrations of doped Al, respectively. Photocatalytic activity of nanoparticles was measured by degradation of methyl orange as a pollutant under radiation of ultraviolet (UV). The experimental test results indicate that the best photocatalytic performance is at of 5% of Al. Furthermore, the doped ZnO nanoparticles have more activity in visible area compared with undoped nanoparticles. The absorption amount in this area increases by raising the Al concentrations. Furthermore, the band gap of the particles decreases from 3.22 eV to 2.93 eV by increasing Al percentage. 相似文献
18.
Wei Wang Honglie Shen Feng Jiang Xiancong He Zhihao Yue 《Journal of Materials Science: Materials in Electronics》2013,24(6):1813-1817
In this study, ball cactus-like kesterite Cu2ZnSnS4 microparticles were successfully and rapidly fabricated by chemical solution with microwave irradiation using ethylene glycol as a solvent. And then CZTS thin film was prepared by ink-print method. The samples were characterized by means of X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, energy dispersive spectrometer, scan electron microscopy, transmission electron microscopy, and UV–vis-NIR spectroscopy. The results showed that the as-prepared microparticles had single phase, stoichiometric composition, a ball cactus-like shape with a diameter about 300 nm and that CZTS thin film had large grains and high crystallinity. 相似文献
19.
《Advanced Powder Technology》2014,25(5):1554-1559
For the first time, hierarchical doughnut-shaped Cu2ZnSnS4 (CZTS) microparticles were synthesized by microwave-assisted solution method. N,N-dimethylformamide and polyvinylpyrrolidone (PVP) were used as solvent and stabilizing agent respectively, and the results showed that PVP played an important role in the formation of hierarchical nanostructures. Structural analysis by X-ray diffraction and Raman studies confirmed the formation of single phase kesterite CZTS. Morphological analysis by scanning electron microscope showed doughnut-shaped CZTS microparticles composed of large number of interpenetrating nanoplates. Optical analysis by UV–Vis diffused reflectance spectra showed strong absorption in the visible region with an optical band gap of 1.54 eV. Asymmetric broad emission bands around 1.55 eV and 1.30 eV were observed in the photoluminescence spectrum. A possible formation mechanism for doughnut-shaped CZTS microparticles was put forward and discussed briefly. 相似文献
20.
High saturation magnetization (>90 emu/g) multi-walled carbon nanotubes (MWCNTs) and Fe4N nanoparticles composite were successfully synthesized by gas nitriding at 550 °C. Almost all Fe4N nanoparticles were evenly distributed inside the carbon nanotubes and formed a special composite microstructure. This composite microstructure shows excellent soft magnetic property, structural stability, and chemical stability at room temperature. The investigations of electromagnetic and microwave absorption performances indicate that microwave absorbing capacity of low frequency band of MWCNTs were greatly improved by addition of Fe4N nanoparticles. 相似文献