Structural, Optical and Thermal Characterization of Non-Stoichiometric Cu2-xSe Nanoparticles (original) (raw)
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IJERT-Structural, Optical and Thermal Characterization of Non-Stoichiometric Cu 2-x Se Nanoparticles
International Journal of Engineering Research and Technology (IJERT), 2020
https://www.ijert.org/structural-optical-and-thermal-characterization-of-non-stoichiometric-cu2-xse-nanoparticles https://www.ijert.org/research/structural-optical-and-thermal-characterization-of-non-stoichiometric-cu2-xse-nanoparticles-IJERTV9IS100047.pdf Fluorescent Cu2-xSe nanoparticles were prepared by a fast, versatile, microwave-assisted solvothermal method using microwave oven. Copper ions were from copper acetate dihydrate, selenite ions were from sodium selenite and reaction medium consisted of ethylene glycol and distilled water. The XRD patterns indicate that all the peaks are matching the peaks of non-stoichiometric Cu1.78Se and the average size of the nanoparticle is found to be 15nm. XRD, SEM, EDX and FTIR studies confirm the morphology and composition of Cu2-xSe nanoparticles. The optical band gap energy of the material was estimated using Tauc relation from UV-Visible spectrum. In the PL spectrum a sharp, intense blue emission peak is observed at 439.6nm. TGA shows that the prepared Cu2-xSe nanoparticles are very stable up to 486 0 C.
Journal of Nanoparticle Research, 2012
The research for tunable synthesis and characterization techniques is important for the investigation of nanomaterials. Herein we developed old precipitation reaction for the morphology-and phasetunable synthesis of copper selenides nanostructures at room temperature, avoiding tedious preparation of selenium precursors, such as selenite or selenosulfate. The molar ratio of Cu 2? and Se sources served the function of a switch for selectively synthesis of stoichiometric CuSe and non-stoichiometric Cu 2-x Se. Nanorod and lath-like CuSe formed with excess of selenium source, while tremella-shaped Cu 2-x Se responded to the 1:1 of Cu 2? /Se or excess of copper source. The structures of nanocrystals, especially the lifelike surface, were characterized in detail by electron microscopy techniques, such as STEM. Novel nanostructures put up the excellent absorption properties in the visible light region, respectively, and could bear potential applications in solar cell devices in the future. This strategy offered a convenient, mild and energy-efficient route for the preparation of other mental chalcogenides nanocrystals with different morphologies or tunable phases.
Langmuir : the ACS journal of surfaces and colloids, 2018
The ability to manipulate the near-infrared (NIR) localized surface plasmon resonance (LSPR) absorbance of copper chalcogenide materials is of utmost importance for applications such as photothermal therapy (PTT). In this work, we manipulate the NIR absorbance of copper selenide (Cu2-xSe) nanoparticles (NPs) by precisely controlling their size and composition. We also introduce a facile method for transferring ultra-small hydrophobic Cu2-xSe NPs into aqueous solution. We then elucidate the relationship between the irradiation wavelength and photothermal conversion efficiency for these materials. The resulting insights can advance the use of copper chalcogenide nanomaterials in PTT applications.
Applied Surface Science, 2013
Influence of reaction conditions on the synthesis of copper selenide (CuSe) nanoparticles and their photo degradation activity is studied. Nearly monodispersed uniform size (23-44 nm) nanoparticles are synthesized by varying the reaction conditions using reflux condensation method. The obtained nanoparticles are characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy and UV-visible absorption spectroscopy. The X-ray diffraction analysis of the sample shows the formation of nanoparticles with hexagonal CuSe structure. The result indicates that on increasing the reaction time from 4 to 12 h, the particle size decreases from 44 to 23 nm, but an increase in the reaction temperature increases the particle size. The calculated band gap E g is ranging from 2.34 to 3.05 eV which is blue shifted from the bulk CuSe (2.2 eV). The photocatalytic degradation efficiency of the CuSe nanoparticles on two organic dyes Methylene blue (MB) and Rhodamine-B (RhB) in aqueous solution under UV region is calculated as 76 and 87% respectively.
ACS Omega, 2021
A rapid, sustainable, and ecologically sound approach is urgently needed for the production of semiconductor nanomaterials. CuSe nanoparticles (NPs) were synthesized via a microwave-assisted technique using CuCl 2 •2H 2 O and Na 2 SeO 3 as the starting materials. The role of the irradiation time was considered as the primary concern to regulate the size and possibly the shape of the synthesized nanoparticles. A range of characterization techniques was used to elucidate the structural and optical properties of the fabricated nanoparticles, which included X-ray diffraction, energydispersive X-ray spectroscopy (EDX), atomic force microscopy, field emission scanning electron microscopy, Raman spectroscopy (Raman), UV−Visible diffuse reflectance spectroscopy (DRS), and photoluminescence spectroscopy (PL). The mean crystallite size of the CuSe hexagonal (Klockmannite) crystal structure increased from 21.35 to 99.85 nm with the increase in irradiation time. At the same time, the microstrain and dislocation density decreased from 7.90 × 10 −4 to 1.560 × 10 −4 and 4.68 × 10 −2 to 1.00 × 10 −2 nm −2 , respectively. Three Raman vibrational bands attributed to CuSe NPs have been identified in the Raman spectrum. Irradiation time was also seen to play a critical role in the NP optical band gap during the synthesis. The decrease in the optical band gap from 1.85 to 1.60 eV is attributed to the increase in the crystallite size when the irradiation time was increased. At 400 nm excitation wavelength, a strong orange emission centered at 610 nm was observed from the PL measurement. The PL intensity is found to increase with an increase in irradiation time, which is attributed to the improvement in crystallinity at higher irradiation time. Therefore, the results obtained in this study could be of great benefit in the field of photonics, solar cells, and optoelectronic applications.
A new simple route for the preparation of nanosized copper selenides under different conditions
In this paper copper selenide nanostructures were synthesized via a simple hydrothermal method based on the reaction between copper salt and SeCl4 in water. The reduction reaction of SeCl4 to Se and then Se2 was carried out by three types of reductants: N2H4.H2O, KBH4, and metallic Zn. Different compositions of copper selenides were obtained by changing the molar ratio of the precursors. At the temperature of 120 1C for a 12 h period of time, when the molar ratio of Cu/Se is 1:1 or 2:1, the product is pure and found to be CuSe and Cu1.8Se, respectively. A mixture of the different phases of copper selenides is obtained by making use of 1:2, 3:2 and 3:1 M ratios between Cu and Se. With an increasing reaction temperature up to 210 1C, the mixture of Cu3Se2 and CuSe is prepared from 1:1 M ratio of precursors. The effects of copper salt, surfactant, amount of hydrazine, reaction time and temperature on the morphology and particle size of products are also investigated. The synthesis can be performed conveniently and safely. The products are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS) analysis. Photoluminescence (PL) is used to study the optical property of copper selenides.
Journal of Crystal Growth, 2010
Nonstoichiometric (Cu 2 À x Se) and stoichiometric (CuSe, b-Cu 2 Se and Cu 2 Se) copper selenide hexagonal nanoplates have been synthesized using different general and convenient copper sources, e.g. copper chloride, copper sulphate, copper nitrate, copper acetate, elemental copper with elemental selenium, friendly ethylene glycol and hydrazine hydrate in a defined amount of water at 100 1C within 12 h adopting the solvothermal method. Phase analysis, purity and morphology of the product have been well studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray diffraction (EDAX) techniques. The structural and compositional analysis revealed that the products were of pure phase with corresponding atomic ratios. SEM, TEM and HRTEM analyses revealed that the nanoplates were in the range 200-450 nm and the as-prepared products were uniform and highly crystallized. The nanoplates consisted of {0 0 1} facets of top-bottom surfaces and {1 1 0} facets of the other six side surfaces. This new approach encompasses many advantages over the conventional solvothermal method in terms of product quality (better morphology control with high yield) and reaction conditions (lower temperatures). Copper selenide hexagonal nanoplates obtained by the described method could be potential building blocks to construct functional devices and solar cell. This work may open up a new rationale on designing the solution synthesis of nanostructures for materials possessing similar intrinsic crystal symmetry. On the basis of the carefully controlled experiments mentioned herein, a plausible formation mechanism of the hexagonal nanoplates was suggested and discussed. To the best of our knowledge, this is the first report on nonstoichiometric (Cu 2 À x Se) as well as stoichiometric (CuSe, b-Cu 2 Se and Cu 2 Se) copper selenide hexagonal nanoplates with such full control of morphologies and phases by this method under mild conditions.
Journal of Alloys and Compounds, 2019
Synthesis of well controlled pure phase of CuS with defined shapes and sizes remains a challenge for effective applications. We studied the role of copper and sulfur source precursors in controlling the size, shape and morphology of CuS nanostructures using synthesized refluxing method. CuS nanoparticles are synthesized by varying Cu(CH 3 COO) 2 .H 2 O, Cu(NO 3) 2 .3H 2 O, CuSO 4 .5H 2 O as copper precursors and CH 4 N 2 S, Na 2 S 2 O 3 .5H 2 O, Na 2 S as sulfur precursors. As synthesized copper sulfide nanoparticles were characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive X-ray (EDX), Ultra Violet-visible spectrophotometer (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), and micro Raman spectroscopy. All precursors result into nano-size single phase covellite copper sulfide, except sodium sulfide as a sulfur source which resulted into mixed phases. Morphology of nano-systems varies (hexagonal plate like, tube like, cluster of nanoparticles, plate like and ball like nanostructures) with varying precursors. TEM images show particle size variation (particle size 20~25 nm). Elemental analysis using EDX confirm that stoichiometric ratio of Cu/S is approximately 1:1 which is in good agreement with the starting molar ratio. FT-IR and Raman spectra confirm the absence of Cu 2 S and the band width of S-S stretch mode is correlated with particle size. Optical energy band gap varies in the range 1.80~2.