Formation Of CuO Nanoparticles Research Articles

Copper oxide nanoparticles (CuO-NPs): Synthesis, characterization and evaluating their ability to remove methylene blue from aqueous solutions without UV irradiation and in the absence of H2O2

In this work, CuO nanoparticles (CuO-NPs) were synthesized at 400 °C using a modification of the polymer complex-Pechini method. Considering the procedure used, a mechanism was proposed to explain the formation of CuO-NPs. The synthesized nanoparticles were characterized using IR, Raman and UV–Vis spectroscopies, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that the sample synthesized contained CuO as the only crystalline phase, with a crystallite size between 9.17 and 14.95 nm, depending on the crystallographic direction and gap energy values of ∼4 eV and ∼5.86 eV. The CuO powder had agglomerates, in the order of microns, and primary particles smaller than 100 nm, with irregular morphology. The CuO synthetized was not stoichiometric and that it had an excess of oxygen, indicating the presence of cation vacancies and/or interstitial oxygen. The study of the capacity of CuO-NPs to remove methylene blue (MB), without irradiating the system with UV–Vis and without the presence of H2O2, showed that these promoted a percent removal of ∼39% in a basic medium (pH ∼9.7).

Low-temperature sintering of multifunctional SiC catalytic membrane for synergistic emission control of toluene and dust

SiC catalytic membranes have shown great potential in dust and atmospheric pollutant emission control. However, their high sintering temperature (up to 1850 °C) and the ‘trade-off’ effect between its gas permeance and catalytic performance have hindered their widespread application. In this study, a high-performance CuO-loaded SiC catalytic membrane was fabricated to address the above issues using a liquid phase sintering and surficial reconstruction (LSSR) strategy. The low melting point of CuO enables the liquid phase sintering of CuO-SiC membrane at a significantly reduced temperature of 1040 °C, and the formation of CuO nanoparticles (CuO-NPs) on bulk CuO in CuO-SiC membrane (CuO-NPs/CuO-SiC) is achieved through a surficial reconstruction process. The resulting CuO-NPs/CuO-SiC catalytic membrane exhibits a high gas permeance of 275.8 m3·m−2·h−1·kPa−1 and a bending strength of 14.2 MPa. The CuO-NPs/CuO-SiC catalytic membrane also displays complete (100 %) toluene oxidation and PM2.5 filtration efficiencies at 280 °C, as well as enhanced water vapor resistance and long-term stability. The LSSR was successfully applied to fabricate an CuO-NPs/CuO-Al2O3 catalytic membrane, which shows complete toluene oxidation and PM2.5 filtration efficiency at 300 °C, demonstrating that LSSR is readily extended to fabricating other ceramic and metal-ceramic-based catalytic membranes.

Biologically mediated synthesis of CuO nanoparticles using corn COB (Zea mays) ash for photocatalytic hydrogen production

This research article reports the green synthesis of copper oxide (CuO) nanoparticles (NPs) using the aqueous extract of corn cob ash from agricultural residue. This agricultural residue was subjected to a calcination for use as a stabilizing agent. As-synthesized NPs were characterized by various methods such as SEM/EDS, FT-IR, XRD and UV–Visible spectroscopy. The results revealed that the corn cob ash extract acts as an excellent stabilizing agent for the formation of CuO NPs. The XRD peaks match the standard X-ray diffraction patterns of CuO, confirming a monoclinic crystal structure. The SEM images revealed that the NPs are agglomerated, porous and with rough edges. Meanwhile, the EDS analysis confirmed the existence of Cu and O elements in NPs synthesized by the green route. The absorbance band is at 350 nm and the band gap is around 1.65 eV. Hydrogen evolution was observed on green synthesized CuO in the photocatalysis measurement.

Copper oxide nanostructures: Preparation, structural, dielectric and catalytic properties

A convenient chemical precipitation route was applied to prepare cupric oxide nanoparticles using copper acetate as precursor material. The influence of the reaction conditions on the formation of CuO nanoparticles was studied. The particle size of cupric oxide varies between 7.79 and 23.83 nm depending on the sodium hydroxide amount. The crystallite size of CuO nanoparticles obtained by electrospinning and calcination was of 42.25 nm. X-ray diffraction, scanning electron microscopy, EDX, XPS, electronic absorption and emission spectra were used to discuss the structural, morphological and optical properties of the CuO nanostructures. The electrical characteristics of CuO nanoparticles were investigated by dielectric and conductivity measurements. The dielectric constant ( ε ′) and loss ( ε ’’) were found to be decreased as the frequency increased. The photocatalytic activity of CuO nanoparticles was investigated following the degradation of ciprofloxacin.

Bio-Construction of CuO Nanoparticles Using Texas Sage Plant Extract for catalytical degradation of Methylene blue Via Photocatalysis

The theme of this research is to highlight the importance of green synthesis for nanomaterials preparation. In citing this statement, herein, we reported bio-synthesis of copper oxide (CuO) nanoparticles by Leucophyllum frutescens leaf extract-mediated reaction along with the study of morphological, optical, structural features and their photocatalytic dye degradation activity of synthesized nanoparticles. The formation of bio-mediated CuO nanoparticles was confirmed by the XRD having crystalline size of 27 nm and monoclinic structure, FTIR presenting absorption band at 673 cm−1. The phase purity was revealed from XRD as there is no extra peak for impurities. The CuO represents the absorption of UV radiations at 380 nm upon UV-DRS studies and band gap energy of 1.48 eV. The morphological studies wereperformed by the FESEM and TEM, both characterized that CuO nanoparticles are spherical in shape. The particle size calculated by particle distribution through FESEM and SEM micrographs was ∼ 25 nm which is in accordance with the crystalline size calculated by XRD. The formation of CuO nanoparticles and phase purity was further validated by the EDX analysis. The metallic existence, phase purity and valency of synthesized nanoparticles confirmed by the XPS. The photocatalytic degradation of methylene blue was studied by CuO under irradiation of visible light. The synthesized CuO degraded the cationic dye in 120 min with the degradation efficiency of 88%. Thus, the proposed work suggests the synthesis of metal oxides nanoparticles via green synthesis is very cost effective and ecofriendly process. The green synthesized CuO nanoparticles are efficient photocatalysts for detection and remediation of organic environmental pollutants in water bodies, presenting their potential towards development of wastewater applications.

Non-doped and transition metal-doped CuO nano-powders: structure-physical properties and anti-adhesion activity relationship.

Bacterial contamination and biofilm formation generate severe problems in many fields. Among these biofilm-forming bacteria, Staphylococcus epidermidis (S. epidermidis) has emerged as a major cause of nosocomial infection (NI). However, with the dramatic rise in resistance toward conventional antibiotics, there is a pressing need for developing effective anti-biofilms. So, fabrication of copper oxide nanoparticles (NPs) is one of the new strategies to combat biofilms. Notably, doped CuO NPs in anti-biofilm therapy have become a hot spot of attention in recent years due to their physicochemical properties. In this context, the present work deals with the investigation of undoped and transition metal (TM)-doped CuO NPs (TM = Zn, Ni, Mn, Fe and Co), synthesized via the co-precipitation method. The synthesized CuO NPs are characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field-emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). Results consistently revealed the successful formation of CuO NPs using the co-precipitation method and confirmed that TM ions are successfully inserted into CuO crystal lattice. We found that doping changes the morphology of the CuO NPs and increases their crystallite size. The XPS results show a non-uniform distribution of the doping concentration, with a depletion or an enrichment of the NP surface depending on the element considered. Furthermore, the anti-adhesive potential of CuO NPs against S. epidermidis S61 biofilm formation is evaluated in this study by crystal violet and fluorescence microscopy assays. All synthesized NPs exhibit considerable anti-adhesive activity against S. epidermidis S61 biofilm. Interestingly, compared to undoped CuO, Fe and Ni-doped oxides show an improved activity when used at high concentrations, whereas Mn-doped CuO is the most efficient at low concentrations. This makes TM-doped CuO a promising candidate to be used in biomedical applications.

Ecofriendly green synthesis, characterization and biomedical applications of CuO nanoparticles synthesized using leaf extract of Capsicum frutescens

The green technology is creating an interest among researchers as they are simple, ecofriendly, and also cost-effective especially in synthesizing nanoparticles. In the present study, CuO nanoparticles were synthesized by taking copper nitrate as precursor and using the leaf extract of Capsicum frutescens as capping and stabilizing agent. The visual observation of dark green color indicated the formation of CuO nanoparticles. The gas chromatograph illustrated the phytochemicals in leaf extract. The synthesized CuO nanoparticles were characterized by various analytical techniques such as UV–visible, X-ray diffraction, Fourier transform infra-red, dynamic light scattering, zeta potential and energy dispersive X-ray analyses. Field emission scanning electron micrographs and transmission electron micrographs illustrated the spherical and rectangular-rod shaped nanoparticles with its diameter (width) ranging from 20 to 40 nm. The antibacterial and biofilm activities against Gram-positive (Bacillus anthracis, and Listeria monocytogenes) and Gram-negative (Klebsiella pneumoniae) bacterial human pathogens showed strong inhibition at 95%, 94% and 92% in 150 μg/mL concentration, respectively. The antioxidant activity revealed high (97%) free radical scavenging property at 80 μg/mL concentration. The anti-inflammatory and anti-diabetic activities showed 90% and 85% efficacy at 500 μg/mL concentration, respectively. These results assured the synthesized CuO nanoparticles by using Capsicum frutescens leaf extract may have applications in the biomedical field.

Tuning structural and optical properties of copper oxide nanomaterials by thermal heating and its effect on photocatalytic degradation of Congo Red dye

In this study, Copper oxide (CuO) nanoparticles (NPs) were prepared using the chemical co-precipitation method and treated at different calcination temperatures. The synthesized CuO NPs have been calcinated at 300 °C, 500 °C, and 700 °C. The X-ray Diffraction (XRD) results exhibited a decrease in the width of the principle diffraction peak with the temperature rise. Crystallite size was determined by Scherrer’s formula, whereas, Williamson-Hall method presented drastic variation in size indicating the creation of lattice strain with the rise in calcination temperature. Scanning Electron Microscopy (SEM) images showed an increase in grain size and vary from 170 nm – 430 nm. X-ray Energy Dispersive Spectroscopy (EDS) results indicate the formation of CuO NPs and relative Cu contents increased (52.9 to 72.5 Atomic percentage) with temperature. Optical properties are also affected by the calcination temperature and a reduction in bandgap is observed with the increase in temperature. Fourier Transform Infra-red spectroscopy (FTIR) spectra of different samples showed identical bonding behavior and no apparent change in bonding was observed. Photo-degradation of Congo Red dye was performed with CuO NPs treated at different temperatures and NPs treated at 500 °C, have shown maximum degradation efficiency in 75 min under visible light.

Green Synthesis of Copper Nanoparticles Using Cotton.

Copper nanoparticles (CuNP) were obtained by a green synthesis method using cotton textile fibers and water as solvent, avoiding the use of toxic reducing agents. The new synthesis method is environmentally friendly, inexpensive, and can be implemented on a larger scale. This method showed the cellulose capacity as a reducing and stabilizing agent for synthetizing Cellulose–Copper nanoparticles (CCuNP). Nanocomposites based on CCuNP were characterized by XRD, TGA, FTIR and DSC. Functional groups present in the CCuNP were identified by FTIR analysis, and XRD patterns disclosed that nanoparticles correspond to pure metallic Cu°, and their sizes are at a range of 13–35 nm. Results demonstrated that CuNPs produced by the new method were homogeneously distributed on the entire surface of the textile fiber, obtaining CCuNP nanocomposites with different copper wt%. Thus, CuNPs obtained by this method are very stable to oxidation and can be stored for months. Characterization studies disclose that the cellulose crystallinity index (CI) is modified in relation to the reaction conditions, and its chemical structure is destroyed when nanocomposites with high copper contents are synthesized. The formation of CuO nanoparticles was confirmed as a by-product, through UV spectroscopy, in the absorbance range of 300–350 nm.

Biogenic Reduction to Quantum Dot Sized Cuo Nanoparticles by the Extracts of White Flowers and Averrhoa Bilimbi Fruits

Green synthesis of nanoparticles is a widely explored field of research. Many types of biogenic materials have been proposed and employed to synthesize nanoparticles of different metals. Unexploited sources are still there in the nature which can produce wonderful results. The present manuscript is examining two of such sources- the crape jasmine and dwarf white bauhinia flowers. Both of these white colored flowers effectively reduced copper salt to CuO nanoparticles and the catalytic action was enhanced by the addition of Averrhoa bilimbi extract. The results suggest that the different species of plants having same colour produced same effect on the reduction process. By the combined action of fruit and flowers’ extract we could reduce the particle size to many smaller values. This manuscript presents and effective method to produce nanoparticles of extremely smaller size by green synthesis. From the Fourier transform infrared spectra and UV-Visible spectra, the formation of CuO nanoparticles were confirmed and the DLS analysis presented a reduction in the particle size to less than 20 nm.

Biogenic reduction to quantum dot sized CuO nanoparticles by the extracts of white flowers and Averrhoa bilimbi fruits

Green synthesis of nanoparticles is a widely explored field of research. Many types of biogenic materials have been proposed and employed to synthesize nanoparticles of different metals. Unexploited sources are still there in the nature which can produce wonderful results. The present manuscript is examining two of such sources-the Crape Jasmine (CJ) and Dwarf White Bauhinia(DWB) flowers. Both of these white colored flowers effectively reduced copper salt to CuO nanoparticles and the catalytic action was enhanced by the addition of Averrhoa bilimbi extract. The results suggest that the different species of plants having same colour produced same effect on the reduction process. By the combined action of fruit and flowers’ extract we could reduce the particle size to many smaller values. This manuscript presents and effective method to produce nanoparticles of extremely smaller size by green synthesis. From the Fourier transform infrared spectra and UV–Visible spectra, the formation of CuO nanoparticles were confirmed and the DLS analysis presented a reduction in the particle size to less than 20 ​nm.

Doxorubicin-loaded oxidized starch/poly (vinyl alcohol)/CuO bio-nanocomposite hydrogels as an anticancer drug carrier agent

In this paper, the bio-nanocomposites were used as a potential candidate for controlled release of anticancer drug doxorubicin. Formation of CuO nanoparticles in hydrogels was confirmed using FT-IR, XRD, SEM, EDX, TGA and DSC. In addition, gel content, swelling/de-swelling, antibacterial properties, and drug release profiles were evaluated. The swelling and drug release profiles revealed that the amount of drug released and swelling of the hydrogels depended on the oxidized starch content, pH, and CuO nanoparticle content. Prolonged and more controlled drug releases were observed for CuO nanoparticle containing oxidized starch/PVA hydrogels, which increased with the rise in CuO nanoparticle content.

The big effect of a small change: formation of CuO nanoparticles instead of covalently bound Cu(ii) over functionalized mesoporous silica and its impact on catalytic efficiency.

Two different heterogeneous catalysts, one with Cu(ii) covalently bonded to functionalized mesoporous silica (FMS-Cu(II)) and another with CuO nanoparticles immobilized over the same silica (FMS-CuO-np), have been synthesized by a common route but with a minor alteration in the sequence of addition of reagents. It is interesting to find that by merely changing the order of the addition of reagents Cu(ii) can be incorporated into the framework in two different forms. In one case Cu(ii) binds to the N and O donor centers present in the functionalized material whereas in the other case CuO nanoparticles are generated in situ. The materials have been thoroughly characterized by powder X-ray diffraction, nitrogen adsorption/desorption, transmission electron microscopy, thermal analysis, FT-IR spectroscopy, solid state MAS-NMR spectroscopy and atomic absorption spectrophotometric studies. The synthesized products have been examined for their catalytic efficiencies in the oxidation of olefins, as a model case. Styrene, α-methyl styrene, cyclohexene, trans-stilbene and cyclooctene have been used as substrates in the presence of tert-butyl hydroperoxide as the oxidant in acetonitrile medium under mild conditions. The products of the catalytic reactions have been identified and estimated by gas chromatography and gas chromatography-mass spectrometry. The rate of conversion of the substrates for both the catalysts is high and the selectivity is also good. But from comparative studies, it is found that FMS-CuO-np which contains CuO nanoparticles shows better efficiency than FMS-Cu(II). The catalysts have been recycled for five catalytic cycles without showing much decrease in their catalytic activity.

Augmentation of ferromagnetism in CuO–Al2O3 nanocomposite synthesized via solution combustion method

The finite size effect of CuO nanoparticles and their effect on the magnetic behavior of a CuO–Al2O3 nanocomposite synthesized via a solution combustion method are discussed here. It is observed that the introduction of CuO nanoparticles of ∼20 nm in size on the surfaces of Al2O3 nanosheets strongly influences the magnetic moment of the nanocomposite. The X-ray diffraction pattern reveals the presence of a CuO phase in the CuO–Al2O3 nanocomposite. Electron microscopy imaging shows the presence of CuO nanoparticles distributed over the surfaces of Al2O3 nanosheets. Magnetic measurements performed at 5 and 300 K revealed a strong enhancement in the saturation magnetization of the CuO–Al2O3 nanocomposite at both temperatures. This increase is due to the formation of CuO nanoparticles on the surfaces of the Al2O3 nanosheets. These CuO nanoparticles show a ferromagnetic nature due to the uncompensated surface Cu2+ spins of the copper ions. The presence of the Cu2+ state in the CuO nanoparticles in the CuO–Al2O3 nanocomposite was confirmed by X-ray photoelectron spectroscopy (XPS) measurements.

Synthesis and evaluation of the structural, optical, and antibacterial properties of copper oxide nanoparticles

The nanostructured material, due to their outstanding applications in various fields of science and technology; metal and metal oxide nano are exclusively explored in the progress of nanosized materials. The transition metal oxides including CuO is are used for magnetic storage devices, solar energy applications, sensors, as a catalyst in reactions, as electrode materials in supercapacitors and to tune the semiconducting properties of materials. The current work focuses on the synthesis of CuO nanoparticles (NPs) by combustion technique for various annealing (100°C and 300°C) using ascorbic acid as a capping agent. The XRD pattern confirms that the CuO NPs exhibit the monoclinic structure. The optical properties are investigated using UV–Vis absorption spectra. Further, the refractive index, optical dielectric constant and bulk modulus were investigated using the specific empirical model as a function of temperature. The FTIR spectrum shows that the band in the range 450–500 cm−1 confirms the formation of CuO NPs. The SEM images revealed that the spherical surface morphology of the CuO NPs. The Elemental analysis and the particle size were confirmed by elemental dispersive X-ray analysis (EDX) and particle size analyzer. Moreover, the antibacterial activity of CuO nanoparticles was investigated using E. coli, S. typhi, M. luteus, P. fluorescent, S. flexneri, and V. cholera bacteria.

Z-scan studies of Sn doped CuO nano-colloidal suspension

We report synthesis and characterization of l-valine capped Sn doped CuO nanoparticles (NPs). Pure and Sn doped CuO NPs were obtained by chemical co-precipitation method and were calcined at 500 °C for 2 h. X-ray diffraction (XRD) shows formation of crystalline CuO having monoclinic phase with average particle size of 8 nm. Utraviolet-visible (UV-vis) spectroscopy attests the formation of NPs and strong blue shift in the excitonic absorption has been observed for both uncalcined and calcined NPs. All samples show broad excitonic absorption in the wavelength range 351–654 nm due to inter band surface states transitions in CuO NPs. Fourier transform infra-red (FT-IR) spectroscopy confirms the role of l-valine as capping agent. Energy dispersive X-ray (EDX) spectroscopy confirms Sn doping into CuO. Transmission electron microscopy (TEM) attest the formation of CuO NPs having uniform near spherical shape. Third order NLO properties of undoped and Sn doped CuO NPs in the form of colloidal suspension have been investigated using Z-scan technique employing the fundamental wave at 1064 nm of a 7ns mode-locked Nd-YAG laser operating at 10 Hz. Sample with 5% Sn doping is found to possess strong nonlinear optical absorption and refraction due strong quantum confinement effect, TPA, ESA, etc. processess.

Thermal evolution of morphological, structural, optical and photocatalytic properties of CuO thin films

Nanostructured CuO thin films were synthesized by thermal evaporation and annealing. Structural, optical and morphological changes in the CuO film upon annealing and their overall impact on its photocatalytic activity were investigated employing X-ray diffraction, UV–Vis absorption spectroscopy, atomic force microscopy and field emission scanning electron microscopy. Significant modifications in the morphological, optical, structural and photocatalytic behavior of nanostructured CuO thin film were observed upon thermal annealing. Thermal annealing led to the growth of CuO nanoparticles and the average size of CuO nanoparticles increased from 23 nm to 293 nm as the annealing temperature was increased to 600oC. CuO thin film sample annealed at 400 °C exhibited superior photocatalytic activities over other samples for the degradation of malachite green and methylene blue dyes in 120 and 160 min, respectively. The improved photocatalytic behavior of CuO thin film annealed at 400 °C is attributed to its narrower band gap, improved utilization of sunlight and enhanced adsorption of dye due to increased surface area arising from formation of CuO nanoparticles and their aggregates at the surface.

Preparation and characterization of ascorbic acid-mediated chitosan\u2013copper oxide nanocomposite for anti-microbial, sporicidal and biofilm-inhibitory activity

The chitosan–copper oxide (Chi–CuO) biopolymer nanocomposites were synthesized by a simple green chemistry method using ascorbic acid as a reducing and capping agent. The intense peak around 300 nm was observed in the UV–visible spectrum indicating the formation of CuO nanoparticles. The prepared Chi–CuO nanocomposites were characterized using energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), and Fourier transform-infrared spectroscopy (FT-IR). SEM and XRD pattern showed cubic shape for Chi–CuO nanocomposites with average crystalline size of 17 nm, as calculated using Debye–Scherrer’s formula. The FT-IR spectral studies showed the Cu–O bond formation with chitosan to form nanocomposites. Synthesized nanocomposites showed significant anti-microbial activity against Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli and Penicillium notatum, assayed using the agar well diffusion method. It also showed sporicidal activity against B. subtilis and exhibited effective biofilm-inhibitory activity against B. subtilis (69%/100 μg/mL) and P. aeruginosa (63%/100 μg/mL).Graphical abstract

Particularities of the Magnetic State of CuO Nanoparticles Produced by Low-Pressure Plasma Arc Discharge

Copper oxide nanoparticles were produced by direct plasmachemical synthesis in a plasma arc discharge of low pressure. The formation of CuO nanoparticles with an average size of 12 nm and narrow size distribution intervals was determined by using the x-ray diffraction analysis and TEM microscopy methods. It was defined by using a vibration magnetometer and a SQUID magnetometer, that the magnetic properties of CuO nanoparticles with such size were extremely different from the magnetic properties of bulk antiferromagnetic CuO. Structural defects caused the formation of a ferromagnetic state, remaining at least up to the room temperature. The temperature of corresponding antiferromagnetic ordering was significantly decreased (down to ∼ 100 K). Meanwhile, some of the copper surface spins showed a spin-glass behavior at low temperatures.

Effect of concentration of hexamethylenetetramine in structure, microstructure and optical properties of CuO nanoparticles synthesized by hydrothermal route

Structural and optical studies on CuO nanoparticles prepared by hydrothermal route with different concentration of hexamethylenetetramine (HMTA) are reported. Evolution of structure, microstructure and optical properties were studied by X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR) analysis, and UV–visible spectrophotometer. The XRD analysis indicates the formation of CuO nanoparticles with a monoclinic structure. We also note the presence of a second phase Cu(OH)2 considered as impurity. FTIR technique confirms the presence of this phase. XRD analysis watches that the sample with less concentration of HMTA gives higher crystallite size with less strain. Optical absorption analysis indicated a blue shift in the direct band gap which is due to the quantum confinement effect, and a red shift in the indirect band gap which is attributed to the intra-gap defects states. The different optical parameters are calculated. Their values show a remarquable influence of the amine concentration in the properties of CuO nanoparticles.