CuCr2O4 Nanoparticles Research Articles

The role of copper chromite nanoparticles on physical and bio properties of scaffolds based on poly(glycerol-azelaic acid) for application in tissue engineering fields.

Tissue engineering combines suitable cells, engineering methods, and proper biochemical factors to develop functional and biological tissues and repair damaged tissues. In this study, we focused on synthesizing and characterizing a nanocomposite scaffold based on glycerol and azelaic acid (Gl-Az) combined with copper chromite (CuCr2O4) nanoparticles in order to increase the osteogenic differentiation efficiency of human adipose-derived stem cells (hADSCs) on fabricated scaffolds. The degradability and hydrophobicity properties as well as mechanical and thermal behaviors of nanocomposite scaffolds were investigated. Next, the cell toxicity of glycerol, azelaic acid and CuCr2O4 nanoparticles was studied by MTT assay test and acridine orange staining. Finally, the osteogenic differentiation of hADSCs on Gl-Az-CuCr2O4 scaffolds was examined using alkaline phosphatase activity (ALP) and calcium content. The obtained results demonstrated that Gl-Az-1%CuCr2O4 not only showed appropriate mechanical strength, biocompatibility and degradability but also influenced the capability of hADSCs to differentiate into osteogenic lineages. The hADSCs culture in Gl-Az-1%CuCr2O4 showed a significant increase in ALP activity levels and calcium biomineralization after 14days of osteogenic differentiation. In conclusion, the Gl-Az-1%CuCr2O4 nanocomposite could be used as a biocompatible and degradable scaffold to induce the bone differentiation of hADSCs and it could be a promising scaffold in bone regenerative medicine.

Magnetic, Electric and Optical Properties of Ion Doped CuCr2O4 Nanoparticles

The magnetic, electric and optical properties of pure and ion doped CuCr2O4 - bulk and nanoparticles are investigated theoretically. The magnetization Ms and the band gap Eg decrease with increasing particle size. By Co ion doping Ms and the polarization P show a maximum whereas by Pr ion doping they decrease with increasing the doping concentration. The dielectric constant decreases with enhancing Pr dopants. It is shown that the difference between the doping and host ions radii leads to appearing of a compressive or tensile strain and to different exchange interaction constants in the doped state. Eg decreases by Co doping, whereas it increases by Pr doping.

Generation of Hydrogen Gas Using CuCr2O4-g-C3N4 Nanocomposites under Illumination by Visible Light.

In this research, nanocomposites made of CuCr2O4-g-C3N4 accommodating distinct contents of CuCr2O4 (1–4 wt %) nanoparticles (NPs) were endorsed for hydrogen gas production after illumination by visible light in the presence of aqueous glycerol solution. The ultrasonication-mixture method was applied to assure the homogeneous distribution of CuCr2O4 NPs over synthesized mesoporous g-C3N4. Such nanocomposites possess suppressed recombination between the photoinduced charges. High-resolution transmission electron microscopy and X-ray photoelectron spectroscopy examinations affirmed the formation of CuCr2O4-g-C3N4 heterojunctions. The separation between the induced charges and the photocatalytic performance with the CuCr2O4 NP amount were investigated. The CuCr2O4-g-C3N4 heterojunction of 3 wt % CuCr2O4 content was documented as the optimal heterojunction. Upgraded hydrogen gas generation was attained over the optimal heterojunction with the extent of ten and thirty times as those registered for pure CuCr2O4 and g-C3N4 specimens, respectively, under illumination by visible light. The photocatalytic performance acquired by the diverse synthesized specimens was assessed not only by their effectiveness to absorb light in the visible region but also by their potential to separate the photoinduced charges.

Synthesis of copper chromite nanocomposites for electrochemical sensor application

The Copper Chromite Nanocomposites (CuCr2O4 Nanoparticles) was synthesised through hydrothermal technique. Several methods, including UV–visible, powder X-ray diffraction and Fourier transform infrared spectroscopy were employed to characterise the produced CuCr2O4 Nanocomposites. Field emission scanning electron microscopy was used to examine the morphology. The CuCr2O4 nanocomposites modified carbon paste electrode (CuCr2O4 Nanocomposites MCPE) was prepared by combining synthesised CuCr2O4 nanocomposites with carbon paste electrode (CPE) as electrochemical sensor for paracetamol (PC). The cyclic voltammetric technique was used to study experimental studies such as scan rate, concentration, pH and real sample analysis. The CuCr2O4 Nanocomposites MCPE showed an improved electrocatalytic response to PC oxidation. The over potential for oxidation of PC was greatly lowered as compared to bare carbon paste electrode (BCPE), which considerably enhanced the current responsiveness on the CuCr2O4 Nanocomposites MCPE. Scan rate study for PC discusses the process of the electrode was controlled by diffusion. CuCr2O4 Nanocomposites MCPE achieved a linear calibration curve with the range of 5 ​μM to 40 ​μM having the low detection limit and quantification limit values 2.7 ​μM and 9.2 ​μM, respectively. This research demonstrates that the electrochemical oxidation of PC at CuCr2O4 Nanocomposites MCPE is a pH dependent process. CuCr2O4 Nanocomposites MCPE was employed to detect PC in real samples with satisfactory results and high accuracy.

Facile synthesis of CuCr2O4/BiOBr nanocomposite and its photocatalytic activity towards RhB and tetracycline hydrochloride degradation under household visible LED light irradiation

Here we report the development of CuCr2O4/BiOBr nanocomposite photocatalysts for the first time to serve the purpose of rhodamine B (RhB) and tetracycline hydrochloride (TC-HCl) degradation using household visible light emitting diode (LED) light. In this nanocomposite, sol-gel combustion made spherical shaped CuCr2O4 nanoparticles are decorated on BiOBr plates in single pot via precipitation method using cetyltrimethylammonium bromide (CTAB) as the Br source as well as the template. The present investigation highlights a significant advancement to tackle the challenge of visible light induced photocatalytic degradation of harmful organic dye RhB and antibiotic-pollutant TC-HCl. The 20%CuCr2O4/BiOBr nanocomposite exhibits high degradation activity for both RhB (96.0% in 15 min) and TC-HCl (96.7% in 300 min) in presence of LED light with good recycling characteristics. Detailed structural and optical characterization using XRD, BET, FESEM, TEM, HRTEM, EDX, XPS, UV−Vis DRS, PL spectroscopy and Raman spectroscopy have been carried out prior performing photocatalytic activity tests. The structural as well as optical data have revealed a significant improvement in visible light absorption of BiOBr in presence of CuCr2O4. Based on energy band modification at the heterojunction of nanocomposite materials and their radical trapping ability, a plausible mechanistic path of photocatalytic degradation is presented.

Microporous copper chromite thick film based novel and ultrasensitive capacitive humidity sensor

In this paper we report to have developed a microporous Copper Chromite (CuCr2O4) thick film based capacitive humidity sensor that exhibits excellent response in the range of 1%–98% RH at room temperature. CuCr2O4 spinel nanopowder was synthesized by a facile sol-gel technique. The as prepared CuCr2O4 nanopowder was screen printed to develop a thick film and it was sandwiched between two parallel electrodes of silver and copper to develop a parallel plate capacitive sensor. The CuCr2O4 nanoparticles and the thick film were well characterized by XRD, XPS, FTIR spectroscopy, Raman Spectroscopy, FESEM, TEM, EDX, and contact angle measurement. Various electrical parameters of the sensor, viz. Capacitance (Cp), Dissipation (D), Conductance (Gp), Susceptance (Bp), and admittance (Y) were measured at different frequencies ranging from 100 Hz to 1 MHz. It was observed that the optimum operating frequency is 1 kHz. At this frequency the sensor exhibited very high sensitivity, especially in the low %RH range of 1%–40% (∼640 pF change in capacitance), low dissipation loss (<2 for all %RH range), and fast response (∼3.6 s) and recovery times (128 s). Further, the sensor exhibits long-term stability (at least 6 months). The sensor may find commercial applications in food packaging, tea industry, hospitals, power plants etc.

Nanochromates MCr2O4 (M = Co, Ni, Cu, Zn): Preparation, Characterization, and Catalytic Activity on the Thermal Decomposition of Fine AP and CL-20.

The chromate nanoparticles such as CoCr2O4, NiCr2O4, CuCr2O4, and ZnCr2O4 were prepared by a modified sol–gel method. The structural and morphological properties of the chromate nanoparticles were characterized by X-ray diffraction (XRD) and a scanning electron microscope (SEM). The catalytic effects of chromates on the thermal decomposition of fine ammonium perchlorate (FAP) and hexanitrohexaazaisowurtzitane (CL-20) were studied by the TG-DTG measurements. Results show that the addition of CoCr2O4, NiCr2O4, CuCr2O4, and ZnCr2O4 nanoparticles makes the activation energies for the thermal decomposition of FAP decrease by 93.9, 94.0, 83.1, and 67.0 kJ·mol–1, and the thermal decomposition temperatures decrease by 45.0, 24.9, 57.7, and 38.8 K respectively. On the other hand, a similar trend exists in the case of the thermal decomposition of CL-20. Therefore, the addition of nanochromates shows high catalytic efficiency on the thermal decomposition of both FAP and CL-20 components, which would be beneficial to promote the burning rate of propellants containing FAP and CL-20 components.

Structural, morphological and dielectric investigation of spinel chromite (XCr2O4, X = Zn, Mn, Cu &amp; Fe) nanoparticles

The nature of engineering technique has a significant effect on the particle size, particle distribution and thus affects the morphological, electrical and dielectric properties of the materials. In this work, ZnCr2O4, MnCr2O4, CuCr2O4 and FeCr2O4 nanoparticles have been synthesized using wet chemical based sol–gel auto-combustion method. The crystal structure, lattice constant, unit cell volume, X-ray density and porosity of the calcined powder samples were determined from the data obtained from X-ray diffractometer. Morphology, grains size and distribution of the grains were analyzed using field emission scanning electron microscopy. Dielectric response of the samples was checked in the frequency range of 20 Hz to 20 MHz. The analysis of real and imaginary dielectric constant and tangent loss revealed a non-linear dielectric behavior of the spinel oxides. A strong frequency dependent response of different electroactive regions was found by impedance spectroscopy. Hopping of charge carriers in the conduction mechanism of spinel chromites was analyzed from the variation of ac conductivity with frequency.

Investigation of the synergic effect of silver on the photodegradation behavior of copper chromite nanostructures

Pure copper chromite nanoparticles were prepared through an efficient route using copper nitrate and chromium nitrate. For the first time, various amino acids were employed as capping agents in the presence of propylene glycol and ethylene glycol in order to prepare these nanostructures. A number of experiments were performed to examine the effect of stabilization agents, alkaline agents and connecting agents on the shape, grain size and photodegradation behavior of CuCr2O4. The results showed that the type of stabilization agent and reducing agent creates numerous changes in terms of the size and photocatalytic performance of copper chromite. The effects of several factors, including the type of pollutant, grain size of CuCr2O4 nanostructures, pH and dosage of dye, on the photocatalytic behavior of copper chromite nanostructure were evaluated. Solutions of methylene blue, methyl orange and rhodamine B were employed as model contaminants. The maximum photocatalytic activity of the CuCr2O4 nanostructure was achieved for the rhodamine B contaminant under UV irradiation. When the CuCr2O4/Ag nanostructure was used instead of CuCr2O4 nanoparticles, the photocatalytic activity during the degradation of rhodamine B increased from 76 to 91%.

Investigation of size and medium effects on antimicrobial properties by CuCr2O4 nanoparticles and silicone rubber or PVDF

The purposes of this study were investigating the size and medium influences on the antibacterial characteristics. Accordingly, the bare and resized nanoparticles were prepared and characterized and then blended using silicon rubber or polyvinylidene fluoride (PVDF) to investigate antibacterial features. The x-ray powder diffraction (XRD) patterns confirmed that the nanoparticles were synthesized. The scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) analysis were used to determine the morphology and chemical structure of the obtained nanoparticles, respectively. Finally, the antibacterial properties of the bare or resized CuCr2O4 nanoparticles were investigated using Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The results demonstrated that the silicone rubber composites have the ability to inhibit the growth of the E. coli and S. aureus while the PVDF mediums have no effect on it. Interestingly, the results exposed the size effect on the antibacterial properties of the CuCr2O4 nanoparticles.

Preparation and Characterization of Copper Chromium Oxide Nanoparticles Using Modified Sol‐Gel Route and Evaluation of Their Microwave Absorption Properties

In this study, simple, broadband, robust, and affordable microwave absorbing nanocomposites are prepared using CuCr2O4 nanoparticles as guests and silicone rubber or poly(vinylidene fluoride) (PVDF) as host. Firstly, the pristine and modified CuCr2O4 nanoparticles are obtained by the conventional citrate gel method in the absence and presence of sucrose as a novel capping agent in the experimental steps. X‐ray powder diffraction (XRD) patterns confirms that the CuCr2O4 nanoparticles are synthesized. Moreover, morphologies, chemical functional groups, and optical properties are studied using field emission scanning electron microscopy (FE‐SEM), Fourier transform infrared (FT‐IR), and diffuse reflection spectroscopy (DRS), respectively. The vibrating sample magnetometer (VSM) analysis reveals weak magnetic properties for the nanoparticles and confirms that the capping agent change the magnetic properties. Finally, bare and modified copper chromium oxide nanoparticles are separately molded with silicone rubber or PVDF to compare dipole and interfacial polarization. Besides, using a vector network analyzer (VNA) along the x and ku‐band frequency, novel organic precursor effects on their microwave absorption properties are examined. According to the obtained results, the maximum reflection loss of the modified CuCr2O4/PVDF is −65.57 dB at 14 GHz with 2 mm thickness and the CuCr2O4/PVDF nanocomposite absorbs a bandwidth of 7.73 GHz more than 10 dB with a thickness of 2 mm. Interestingly, novel one type filler lead to significant microwave absorbing properties as well as organic capping agent reinforced maximum microwave absorption also PVDF improves absorption bandwidth.

Design and development of a novel lanthanum inserted CuCr2O4 nanoparticles photocatalyst for the efficient removal of water pollutions

In the present research study, the insertion of lanthanum in the CuCr2O4 lattice structure have been reported for the first time. Lanthanum insertion performed via a simple preparation approach. Different loading percentages of lanthanum in the CuCr2O4 crystal structure have been successfully performed. To confirm the correct structure of as prepared materials we have been utilized the various characterization methods including x-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), Diffuse reflectance (DRS) and Vibrating Sample Magnometer (VSM). The photocatalytic behavior of the as-synthesized nanostructures were evaluated for the destruction of RhB and MO organic contaminants under incident visible light illumination. The prepared catalyst demonstrated the 98 and 99% photocatalytic degradation for the destruction of Rh B and MO organic dyes. According to the trapping experiments the superoxide anion radicals was the main reactive species in the photocatalytic process. To further addressing the enhancement in the photocatalytic ability of the prepared phtotocatalyst for the decontamination of water contaminants a suggested photocatalytic mechanism based on the obtained experiments and tests have been proposed. According to the reusability evaluation tests the synthesized catalyst can be recycled six times without remarkable loss in the photocatalytic performance.

Sol-gel assisted synthesis of CuCr2O4 nanoparticles: An efficient visible-light driven photocatalyst for the degradation of water pollutions

In this study, a novel template assisted synthesis of CuCr2O4 nanoparticles have been designed and developed for the first time. To reaching an optimum amount the influence of various important parameters ware examined. The as-prepared CuCr2O4 and capped CuCr2O4 nanoparticles have been characterized with the utilization of various techniques including Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and Diffuse reflectance spectroscopy (DRS). The as-prepared CuCr2O4 structures have been employed for the photocatalytic degradation of Methylene blue (MB) and Methyle orange (MO) organic contaminants. Significantly, the templated CuCr2O4 nanoparticles have been demonstrated the enhanced photocatalytic activity compared with the CuCr2O4 nanoparticles. Several noteworthy characteristics of the present research study are high amount of light harvesting, efficient separation of photogenerated electron-hole pairs and adsorption properties. Additionally, the synthesized CuCr2O2 nanoparticles behaves as a throughly heterogeneous catalyst and can be employed for industrial affairs.

Synthesis of CuCr2O4/Reduced Graphene Oxide Composite: A Green Catalyst for Selective Oxidation of Cyclohexane to Cyclohexanone with Hydrogen Peroxide

AbstractCuCr2O4/reduced graphene oxide (rGO) composites were prepared using a two‐step method. Detailed characterizations of the material were performed with X‐ray diffraction (XRD), Zeta potential, Fourier transform infrared (FT‐IR), transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), Raman spectra, and Thermal Gravimetric Analyzer (TGA). The characterizations showed that the ∼50 nm CuCr2O4 nanoparticles were successfully supported on the rGO via static electricity. The TGA results showed that the quality of rGO in composites was around 10%. The experimental results showed that the catalysts obtained high catalytic activity for the selective oxidation of cyclohexane to cyclohexanone with H2O2. The catalyst obtained a conversion rate of cyclohexane of up to 95.8%. 78.1% cyclohexanone selectivity was obtained. The catalyst had good cycling stability after 5 reuses. Compared to the other composite materials, the catalyst had high catalytic activity for the selective oxidation of cyclohexane to cyclohexanone.

Graphitic carbon nitride nanosheets decorated with CuCr2O4 nanoparticles: Novel photocatalysts with high performances in visible light degradation of water pollutants

In this paper, CuCr2O4 nanoparticles were decorated on the surface of g-C3N4 nanosheets (g-C3N4-NS) by a facile refluxing process. The structure, composition, morphology, optical, textural, and thermal properties were characterized by XRD, EDX, SEM, TEM, UV–vis DRS, FT-IR, XPS, PL, BET, and TGA techniques. The photocatalytic performance of g-C3N4-NS/CuCr2O4 nanocomposites was assessed by degrading RhB and MB dyes and phenol under visible-light illumination. When the loading amount of CuCr2O4 was 10 wt%, the nanocomposite exhibited the highest activity. Activity of the g-C3N4-NS/CuCr2O4 (10%) nanocomposite refluxed for 3h and calcined at 520°C for 4h was almost 11.8 and 4.8 times greater than those of the bulk g-C3N4 and g-C3N4-NS photocatalysts in degradation of RhB, respectively. In the prepared nanocomposites, nanosheets of g-C3N4 act not only as CuCr2O4 support, but also as co-catalyst. The novel visible-light-active photocatalyst has considerable stability and it can be reused for five times without obvious loss of its photocatalytic activity.

INVERSE CO-PRECIPITATION SYNTHESIS OF COPPER CHROMITE NANOPARTICLES

In this study, copper chromite (CuCr2O4) nanoparticles was prepared by inverse co-precipitation method. In this method, cupric nitrate trihydrate, (Cu (NO3)2.3H2O) and chromium nitrate nonahydrate, (Cr (NO3) 3.9H2O) with a mole ratio of 1:2 were used. Characterization of CuCr2O4 nanoparticles was performed by Fourier Transform Infrared Spectroscopy (FT-IR), Raman Spectroscopy, X-ray Diffraction Spectroscopy (XRD), Thermo-Gravimetric/Differential Scanning Calorimetry (TG-DSC), and Field Emission Scanning Electron Microscopy (FE-SEM). The results show that CuCr2O4 crystal can be obtained at temperature 520 °C. Also, phase structure of the CuCr2O4 depends on both Cu:Cr molar ratio and temperature in the starting reactants. Based on this method and under optimum conditions, the temperature for calcination (520 oC), the crystallite size of nanoparticles (18 nm), the spherical structure particles (30 to 70 nm) were obtained.

Facile synthesis of spinel CuCr2O4 nanoparticles and studies of their photocatalytic activity in degradation of some selected organic dyes

Copper chromite (CuCr2O4) spinel nanoparticle catalysts have been successfully synthesized employing urea assisted co-precipitation followed by calcination. The synthesized nanoparticles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and N2 adsorption-desorption isotherm (BET). The XRD pattern revealed formation of tetragonal body-centered CuCr2O4 and TEM image showed quasi-spherical particles of size 5–35 nm. The photocatalytic activity of CuCr2O4 was evaluated in degradation of some organic dyes such as methylene blue (MB), methyl orange (MO), and rhodamine B (RhB), without and with the assistance of H2O2 under solar irradiation. The CuCr2O4 photocatalysts showed high activity in degradation of RhB (93.6%) and MO (92.3%), but low activity in degradation of MB (80.6%). The catalyst reusability was tested by conducting the degradation of RhB dye with the spent catalyst and it was observed that the catalyst did not show any significant loss in its activity even after five cycles.

Preparation and light-controlled resistive switching memory behavior of CuCr2O4

In this work, CuCr2O4 nanoparticles were successfully prepared by an improved hydrothermal process, and a resistive switching memory behavior with Ag/CuCr2O4/fluorine-doped tin oxide structure is demonstrated. Specially, the resistive switching memory characteristics can be controlled by white-light illumination. The device can maintain superior stability over 100 cycles with an OFF/ON-state resistance ratio of about 103 at room temperature. This study is useful for exploring the promising light-controlled resistive switching memory device in the development of resistive switching random-access memory. We demonstrate a resistive switching device based on Ag/CuCr2O4/FTO structure, and the device shows light-controlled resistive switching memory characteristics.

Copper chromite nanoparticles as an efficient and recyclable catalyst for facile synthesis of 4,4'-(arylmethanediyl)bis(3-methyl-1H-pyrazol-5-ol) derivatives

In this study, pure spinel nanoparticles of copper chromite (CuCr2O4) were synthesized by coprecipitation method. These nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, and FTIR. CuCr2O4 nanoparticles were found to be an efficient catalyst for the synthesis of 4,4'-(arylmethanediyl)bis(3-methyl-1H-pyrazol-5-ols) via pseudo-five-component reaction of aldehydes, hydrazine hydrate, and ethyl acetoacetate. The present methodology offers several advantages such as excellent yields, simple procedure, and mild conditions. The catalyst can be reused at least five times without any obvious change in its catalytic activity.

C–N cross-coupling reaction catalysed by reusable CuCr2O4 nanoparticles under ligand-free conditions: a highly efficient synthesis of triarylamines

A convenient, efficient and ligand-free method for the C–N coupling reaction of anilines and aryl iodides was performed using CuCr2O4 nanoparticles.