Hierarchical CuO/ZnO Membranes for Environmental Applications under the Irradiation of Visible Light (original) (raw)
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AIP Advances, 2015
Zn x Cu 1−x O (where x= 0, 0.01, 0.03, 0.05, 0.07 and 0.1 mol%) hierarchical nanostructures have been prepared via soft chemical route. X-ray diffraction (XRD) results of the synthesized samples reveal the monoclinic structure of CuO without any impurity related phases. The micro-structural parameters such as crystallite size and microstrain have been strongly influenced by Zn doping. Scanning electron microscope (SEM) analyses depict the formation of hierarchical nanostructures having average particle size in the range of 26-43 nm. The surface area of CuO nanostructures has been reduced systematically with the increase in Zn content which is linked with the variations in particle size. An obvious decrease in the optical band gap energy of the synthesized CuO hierarchical nanostructures has been observed with Zn doping which is assigned to the formation of shallow levels in the band gap of CuO and combined transition from oxygen 2p states to d sates of Cu and Zn ions. The bactericidal potency of the CuO hierarchical nanostructures have been found to be enhanced remarkably with Zn doping.
Materials, 2017
In this work we have demonstrated a facile formation of CuO nanostructures on copper substrates by the oxidation of copper foil in ethylene glycol (EG) at 80 °C. On immersing a prepared CuO film into a solution containing 0.1 g Zn(acac)2 in 20 mL EG for 8 h, ZnO flower-like microstructures composed of hierarchical three-dimensional (3D) aggregated nanoparticles and spherical architectures were spontaneously formed at 100 °C. The as-synthesized thin films and 3D microstructures were characterized using XRD, SEM, and EDS techniques. The effects of sodium dodecyl sulphate (SDS), cetyltrimethylammonium bromide (CTAB), and polyethylene glycol (PEG) 6000 as surfactants and stabilizers on the morphology of the CuO and ZnO structures were discussed. Possible growth mechanisms for the controlled organization of primary building units into CuO nanostructures and 3D flower-like ZnO architectures were proposed. The hydrophobic property of the products was characterized by means of water contact...
Advanced Powder Technology, 2017
CuO nanostructures with different morphology were formed on copper substrate by in situ crystallization one-step process via chemical method at room temperature. The as-grown copper oxide nanostructure films were characterized using X-ray diffraction (XRD), Fourier transform-infra red spectroscopy (FT-IR) and scanning electron microscope (SEM) analysis. The XRD and FT-IR analysis confirm the formation of monoclinic CuO nanostructures. SEM images show gradual development of nanostructures of copper oxide with different morphology. A possible growth mechanism was also proposed here. The photo catalytic activity of this CuO nanostructure films was evaluated by monitoring the photo-degradation of salicylic acid. Also antibacterial activity of these films was studied against gram-positive and gram-negative bacteria's. Results demonstrated that CuO thin film possesses good photo catalytic as well as antibacterial activity. Being low cost and easily available material, CuO nanostructures might have promising applications in the field of environmental remediation for organic pollutant degradation.
Chinese Physics B, 2016
Zn 1−x Cu x O (x = 0.00, 0.01, 0.03, and 0.05) nanoparticles are synthesized via the sol-gel technique using gelatin and nitrate precursors. The impact of copper concentration on the structural, optical, and antibacterial properties of these nanoparticles is demonstrated. Powder x-ray diffraction investigations have illustrated the organized Cu doping into ZnO nanoparticles up to Cu concentration of 5% (x = 0.05). However, the peak corresponding to CuO for x = 0.01 is not distinguishable. The images of field emission scanning electron microscopy demonstrate the existence of a nearly spherical shape with a size in the range of 30-52 nm. Doping Cu creates the Cu-O-Zn on the surface and results in a decrease in the crystallite size. Photoluminescence and absorption spectra display that doping Cu causes an increment in the energy band gap. The antibacterial activities of the nanoparticles are examined against Escherichia coli (Gram negative bacteria) cultures using optical density at 600 nm and a comparison of the size of inhibition zone diameter. It is found that both pure and doped ZnO nanoparticles indicate appropriate antibacterial activity which rises with Cu doping.
Structural, morphological, optical and antibacterial properties of pentagon CuO nanoplatelets
Journal of Sol-Gel Science and Technology, 2018
Pure ZnO and Mn-doped ZnO nanoparticles were synthesized by Co-precipitate method. The structural characterizations of the nanoparticles were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. UV-Vis, FTIR and photoluminescence (PL) spectroscopy were used for analysing the optical properties of the nanoparticles. XRD results revealed the formation of ZnO and Mn-doped ZnO nanoparticles with wurtzite crystal structure having average crystalline size of 39 and 20 nm. From UV-Vis studies, the optical band-gap energy of 3.20 and 3.25 eV was obtained for ZnO and Mn-doped ZnO nanoparticles, respectively. FTIR spectra confirm the presence of ZnO and Mn-doped ZnO nanoparticles. Photoluminescence analysis of all samples showed four main emission bands: a strong UV emission band, a weak blue band, a weak blue-green band and a weak green band indicating their high structural and optical qualities. The antibacterial efficiency of ZnO and Mn-doped ZnO nanoparticles were studied using disc diffusion method. The Mn-doped ZnO nanoparticles show better antibacterial activity when higher doping level is 10 at% and has longer duration of time.
2019
Synthesis of highly efficient antibacterial agents has become highly important due to emergence of antibiotic resistance. Herein, Pristine ZnO and ZnO-CuO nanocomposite has been synthesized by simple chemical co-precipitation method and characterized by X-ray diffraction (XRD), microscopic and spectroscopic techniques. The prepared ZnO-CuO nanocomposite is composed of two dimensional nanosheets consisting of hexagonal ZnO and monoclinic CuO crystal phases present in coexistence. Moreover, a minute presence of Cu 5 Zn 8 cubic phase has been evident in the XRD pattern of ZnO-CuO nanocomposite. Fourier Transform Infrared Spectroscopy (FTIR) spectrum of the prepared nanocomposite has revealed the presence of vibrational modes related to both Z-O and Cu-O. Photoluminescence (PL) investigations depicted the formation of huge amounts of surface defects in ZnO-CuO nanocomposite as compared to pristine ZnO nanostructures. The prepared ZnO-CuO nanocomposite has efficiently killed Methicillin resistant Staphylococus aureus (s. aureus) bacterium by producing 24 mm of zone of inhibition (ZOI) comparing to 7 mm produced by pristine ZnO. The superior antibacterial activity of ZnO-CuO nanocomposite has been attributed to oxidative stress generated by electron transfer pathway and reactive oxygen species (ROS) generation.
Scientific Reports
Biopolymers provide versatile platforms for designing naturally-derived wound care dressings through eco-friendly pathways. Eggshell membrane (ESM), a widely available, biocompatible biopolymer based structure features a unique 3D porous interwoven fibrous protein network. The ESM was functionalized with inorganic compounds (Ag, ZnO, CuO used either separately or combined) using a straightforward deposition technique namely radio frequency magnetron sputtering. The functionalized ESMs were characterized from morphological, structural, compositional, surface chemistry, optical, cytotoxicity and antibacterial point of view. It was emphasized that functionalization with a combination of metal oxides and exposure to visible light results in a highly efficient antibacterial activity against Escherichia coli when compared to the activity of individual metal oxide components. It is assumed that this is possible due to the fact that an axial p–n junction is created by joining the two metal ...
Synthesis CuO-ZnO nanocomposite and its application as an antibacterial agent
IOP Conference Series: Materials Science and Engineering, 2017
The synthesis of CuO-ZnO composites and their application as anti-bacterial have been conducted. Nanocomposite CuO-ZnO was synthesized using sol-gel method. The nanocomposite products were characterized by XRD, DR-UV, SAA, FTIR, SEM-EDX. The results of the XRD analysis showed that the CuO-ZnO composite has a nanometer size with the average of 15.99 nanometer. The DR-UV analysis showed that the CuO-ZnO composite has a band-gap of 2.28 eV in the average. The analysis of SAA showed that the CuO-ZnO has a surface area of 23.20 m 2 /g in average. FTIR investigation revealed that the vibration of ZnO was observed at 432.05 cm-1 whereas CuO at 524.64 cm-1 and 594, 06 cm-1. The SEM-EDX analysis showed that the ZnO has a hexagonal structure whereas the CuO has a monoclinic structure. The CuO-ZnO nanocomposite has the ability as an antibacterial against S. aureus as gram-positive and E. coli as Gram-negative bacteria.
Ceramics International, 2019
Cu@ZnO is an important class of material with applications as catalysts, photocatalysts, optoelectronic devices and antimicrobial agents. Because of its potential for large-scale applications and its high redox activity, detailed examination of the properties and risk assessment of this class of materials should be performed. In this work, Cu@ZnO composites were synthesized using a twostep procedure. ZnO crystalline nanostructured materials were prepared within minutes by a solvothermal microwave-assisted method. Deposition of copper nanoparticles on the surface of ZnO was conducted by reduction of Cu 2+ in ethylene glycol (EG). Copper nanoparticles with different morphologies (needle-like and spheres) were deposited on the surface of ZnO. The antibacterial activity of Cu@ZnO composites was evaluated using E. coli and S. aureus as model organisms. The Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) were evaluated for Cu@ZnO composites under visible light radiation (VLR) and in the dark (D). The composites exhibit antibacterial activity under VLR at low concentrations: 250 µg/mL and 750 µg/mL for E. coli, and 250 µg/mL and 500 µg/mL for S. aureus. Copper nanoparticles exert antibacterial activity and can be used to inhibit the growth of microorganisms in the absence of irradiation of Cu@ZnO material. Better antibacterial activity of Cu@ZnO material was achieved under radiation, demonstrating the synergic activity of Cu and ZnO materials for disinfection. Toxicity of the material was assessed towards Daphnia magna (D. magna) and Lecane papuana (L. papuana). Composites exert toxicity at lower concentrations than ZnO, observing LC50 values for L. papuana of 79.
Journal of Solid State Chemistry, 2012
Electrospun copper based composite nanofibers were synthesized using the copper acetate/polyvinyl alcohol/water solution as starting material. Synthesized composite nanofibers were sintered at 500 1C to obtain CuO nanofibers. XRD, FTIR and XPS techniques were used to confirm the presence of pure CuO nanostructures. The effect of annealing cycle on the crystalline structure of the CuO nanofibers was analyzed and observed that the decrease in crystallite size with an increase in the dwelling time improved the orientation of the CuO crystallite. The blue-shift in the band-gap energies of CuO nanofibers was observed as a result of quantum confinement from bulk CuO (1.2 eV) to one dimensional (1D) nanostructures ( $ 1.746 eV). The catalytic activity of the CuO fibers for the degradation of methyl orange was carried out and as a blocking layer in ZnO based DSSC was fabricated and observed a $ 25% increase in the current density.