Thermal Behavior and Decomposition of Copper Sulfide Nanomaterial Synthesized by Aqueous Sol Method (original) (raw)
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Materials Science in Semiconductor Processing, 2016
We report the synthesis of CuS nanoparticles using [Cu(butdtc) 2 ] as single source precursor thermolysed at two different temperatures. The products were characterized by UV-vis absorption spectroscopy, X-ray diffraction, Transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray analysis and atomic force microscopy. The absorption spectra of the CuS nanocrystals are blue shifted and the XRD were indexed to the hexagonal phase of CuS with nanoparticles obtained at 120°C showing well defined crystalline structure compared to those obtained at 180°C. Transmission electron microscopy images showed particles that are almost spherical in shapes with average crystallite sizes of 21-38 nm for CuS1 prepared at 180°C and 3-7 nm for CuS2 prepared at 120°C and confirms that the chosen reaction temperature determine the crystallite sizes of the nanoparticles.
Influence of Precursor Type and Concentration on the Synthesis of Copper Sulfide Nanoparticles
2017
Copper sulfide nanoparticles were successfully synthesized on the base of functionalized nitrile butadiene rubber (FNBR) at room temperature by the successive ionic layer adsorption and reaction (SILAR) method using CuSO4×5H2O, CuCl2×2H2O aqueous solutions as a copper precursors; Na2S×9H2O and thiourea [(NH2)2CS] aqueous solutions as sulfur precursors. X-ray diffractometer (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDX), ultraviolet–visible (UV–Vis) and Fourier transform infrared (FTIR) spectrometer were used to characterize the products. Obtained copper sulfide nanocomposites were heated at 100oC temperature in a vacuum.
Synthesis and characterization of Cu7S4 (anilite) obtained from copper:thiosulfate system
The system Cu(CH3COO)2∙H2O and Na2S2O3·5H2O in a molar ratio 1:1, in 50 mL H2O at room temperature (25 oC) was used to obtain the thiosulfate complex compound ({Na[Cu(S2O3)]}n). After the thiosulfate compound separation, the obtained filtrate was submitted to hydrolytic decomposition at 80oC and pH==11-11.5.The non-stoichiometric copper sulfide Cu7S4 nanocrystallites obtained by hydrolytic decomposition of filtrate were characterized by chemical elemental analysis, X-ray powder diffraction, scanning electron microscopy and IR spectroscopy. The average diameter of the obtained particles varied between 80-110 nm. Their thermal stability in air, studied by nonisothermal techniques together with IR spectroscopy in order to identify phases from different thermal decomposition stages was also investigated. It was established that Cu7S4 is converted to Cu1.8S which is stable in a relatively large temperature range 103-240oC. Furthermore, a five-stepped oxidation to 0.42CuSO4 0.52CuO·CuSO4 occurs. At temperatures higher than 635ºC the formed oxysulfates decompose to CuO. Comparative with the thermal stability of CuS [1] the oxidation process of lower sulfur content sulfides to oxysulfates starts with ~70ºC lower.
Synthesis and characterization of copper sulfide nanocrystallites with low sintering temperatures
Journal of Materials Chemistry, 2008
New copper sulfide nanocrystals with threedimensional (3D) flower-shape were synthesized by using copper acetate (Cu(ac) 2 ) and citric acid (cit) and thiourea (Tu) as precursors at 160°C in an anhydrous ethanol by a solvothermal route. The structure and properties of as-prepared products were characterized by X-ray powder diffraction, transmission electron microscopy, field emission scanning electron microscope and scanning electron microscope. The optical properties of copper sulfide nanocrystals were examined by UV-vis and FTIR. The crystal growth mechanism was also proposed.
Applied Nanoscience, 2011
CuS nano/submicro materials with different morphologies were synthesized with spherical, tubular, leaflike and strip type structures in a simple aqueous system under microwave irradiation and sunlight and employing Cu (CH 3 COO) 2 , CuSO 4 Á5H 2 O, CuCl 2 , and as copper source and H 2 NCSNH 2 , Na 2 S 2 O 3 Á5H 2 O and CH 3 CSNH 2 as sulfur sources. The starting materials were used without assistance of any surfactant or template. An X-ray powder diffraction pattern confirms that the product was CuS with hexagonal phase. Scanning electron microscopy was used to observe the morphologies of the product. Different Phase transitions in CuS with respect to temperature are studied by DSC/TGA. The dependence of morphologies of product on different experimental conditions was also discussed.
Thermal behaviour of CuS (covellite) obtained from copperthiosulfate system
Journal of thermal …, 2007
Thermal behaviour of CuS (covellite) obtained from the Cu(CH 3 COO) 2 ·H 2 O and Na 2 S 2 O 3 ·5H 2 O system, working at different molar ratio (1:6 and 1:4) in presence/absence of NH 4 VO 3 , was studied. It was established that the presence of vanadium in the system induces a densification of CuS nodules, but do not change the hexagonal CuS structure. It has an important influence in thermal behaviour of copper sulfide CuS obtained also. The morphological characteristics of CuS play an important role in the thermal stability and the stoichiometry of the thermal decompositions.
Synthesis and structural studies of copper sulfide nanocrystals
Results in Physics, 2016
We report the synthesis and structural studies of copper sulfide nanocrystals from copper(II) dithiocarbamate single molecule precursors. The optical studies of the as-prepared copper sulfide nanoparticles were carried out using UV-Visible and photoluminescence spectroscopy. The absorption spectra show absorption band edges at 287 nm and exhibit considerable blue shift that could be ascribed to the quantum confinement effects as a result of the small crystallite sizes of the nanoparticles and the photoluminescence spectra show emission curves that are red shifted with respect to the absorption band edges. The structural studies were carried out using powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and atomic force microscopy. The XRD patterns revealed the formation of hexagonal structure of covellite CuS with estimated crystallite sizes of 17.3-18.6 nm. The TEM images showed particles with almost spherical or rod shapes with average crystallite sizes of 3-9.8 nm. SEM images showed morphology with ball-like microsphere on the surfaces and EDS spectra confirmed the presence of CuS nanoparticles.
A facile chemical route for the synthesis of copper sulfide (CuS) nanocrystallites consists of the reaction between Cu(CH3COO)2 .H2O and Na2S2O3 .5H2O. In this reaction the influence of the following factors was pursued: pH value, reaction time, molar ratios, temperature and others. In this article we tried to establish the evolution of the morphology and the shape of the CuS nanocrystallites with the pH value. The CuS nanocrystallites obtained were studied by X ray diffraction, IR spectrometry, TEM – transmission electron microscopy and SAED selected area electron diffraction. The CuS crystallites are formed in spherical or “discoidal” particles which are bonded in bigger aggregates. The reaction pH value was varied from a slightly acid value to an alkali value. In case of alkali medium the crystallites dimensions were smaller than their value in slightly acid medium.
The aggregation of CuS nanoparticles during synthesis by a hassle-free aqueous route under microwave irradiation gave remarkable spherical shape, utilizing Cu(CH 3 COO) 2 ÁH 2 O as the source of copper and Na 2 S 2 O 3 Á5H 2 O, as sulfur source; these materials were used without assistance of any surfactant or template. An X-ray powder diffraction pattern proved that the product is hexagonal CuS phase. The morphologies of the product were observed by scanning electron microscopy. Thermal behavior, different solid state, and chemical conversion in CuS with respect to temperature were studied by DSC/TGA, which confirmed the thermal oxidation of CuS and its conversion into CuO then to Cu 2 O.