Crystalline Copper Research Articles

Biosynthesis of Selenium and Copper Oxide Nanoparticles using Probiotic Bacteria against Food Spoilage Microorganisms

The study’s aim is to synthesize selenium (SeNPs) and copper oxide (CuONPs) nanoparticles using probiotic Lactobacillus acidophilus as a reducing agent. The biosynthesized probiotic Lactobacillus acidophilus selenium and copper oxide nanoparticles were known by color change. The characterization of SeNPs and CuoNPs was completed by Ultraviolet-visible (UV-VIS) spectroscopy, Field Emission Scanning electron microscope (FESEM), Atomic force microscope (AFM), X-Ray diffraction analysis (XRD) and Fourier transform infrared spectroscopy (FTIR). These tests are utilized for detecting stability, morphology, size, crystalline nature and functional groups on nanoparticles prepared surface. Outcomes revealed appearance of the brick-red and green color, representing a specific color of selenium and copper oxide nanoparticles. It was also disclosed that UV-VIS spectroscopy indicated band absorbance at 236 and 264 nanometer of intense surface Plasmon resonance, manifesting the formation and stability of prepared SeNPs and CuONPs. The FESEM image displayed mulit-shapes between spherical and vaulted for selenium and copper oxide nanosized. XRD at 2 theta revealed crystalline selenium and copper oxide nanoparticles where the average size is 75.52-153.22 nm. FTIR revealed the presence of functional groups of the supernatant that act as stabilizing and reducing agents. The antibacterial activity of synthesized nanoparticles was studied against five different bacteria causing food spoilage. As a result of this study, selenium nanoparticle and copper nanoparticles were biosynthized successfully in less time and easy consuming way by green synthesis of the supernatant probiotic Lactobacillus acidophilus.

Epitaxial growth and characterization of copper gallate (CuGa2O4) thin films by pulsed laser deposition

High-quality crystalline copper gallate (CuGa2O4) thin films were grown on c-plane sapphire substrates using the pulsed laser deposition (PLD) technique by optimizing the growth parameters (i.e., temperature, oxygen chamber pressure, and laser energy density). The obtained XRD patterns validated that the preferred orientation of the crystalline CuGa2O4 thin film is along the [111] direction, and the crystallinity of the films improved with increasing substrate temperature while maintaining a constant O2 pressure, as assessed by measuring the full width at half maximum (FWHM) of the prominent (222) plane. Reducing the oxygen pressure leads to the emergence of β-Ga2O3 peaks rather than the CuGa2O4 peaks due to the incomplete oxidation of copper (Cu). Subsequent XRD phi (φ) scans revealed a sixfold rotational symmetry of CuGa2O4 and a 30° epitaxial relationship between the film and the sapphire substrate. X-ray photoelectron spectroscopy (XPS) spectra confirmed the presence of Cu1+, Cu2+, and Ga3+ oxidation states in the films. Increasing laser energy density resulted in the complete oxidation of Cu and an increase in the film thickness from 51.8 nm to 183.4 nm. The direct bandgap of CuGa2O4 films was determined to be approximately 4.50 eV by analyzing the UV–Vis absorbance spectra using the Tauc equation. The refractive index was found to be approximately 2.05 ± 0.01 based on the spectroscopic ellipsometry data. While the impact of increasing laser energy density was negligible on the parameters such as crystal structure, rotational symmetry, oxidation states of gallium (Ga), oxygen (O), bandgap, and refractive index of CuGa2O4 thin film, notable alterations in the oxidation state of Cu and film thickness were observed. The surface roughness (Rrms) measured from AFM images showed a strong correlation with the values derived from ellipsometry analysis.

Green synthesis of copper nanoparticles from Terminalia arjuna (L.) bark extract: Characterization and potential for mercury degradation

The focus of this study is on synthesizing copper nanoparticles through a green approach, utilizing Terminalia arjuna bark extract. The ultra violet (UV) spectral analysis of copper nanoparticles synthesized through environmentally friendly methods revealed distinct absorption peaks at 287 nm, 575 nm, and 898 nm, indicative of significant light absorption. These peaks elucidate the nanoparticles' optical characteristics, shedding light on electronic transitions and surface plasmon resonance phenomena. Fourier transform infrared spectroscopy (FTIR) analysis displayed various peaks, suggesting vibrations associated with copper nanoparticles and functional groups in T. arjuna bark extract. The X-ray diffraction analysis (XRD) data exhibited characteristic peaks corresponding to metallic copper's crystallographic planes, confirming the formation of highly crystalline copper nanoparticles. Atomic force microscopy results depicted surface morphology and particle size distribution. Copper nanoparticles show promise in mercury degradation due to their high surface area and catalytic activity. They interact effectively with mercury ions through adsorption, reduction, and oxidation processes, leading to sequestration or transformation into less toxic forms. Functionalization enhances their affinity towards mercury, while synergies with other nanomaterials boost efficiency. Green synthesized copper nanoparticles offer an eco-friendly solution for effective mercury remediation, promising advancements in sustainable nanotechnological approaches for global environmental sustainability. KEY WORDS: Mercury, Copper, Terminalia arjuna, Remediation Bull. Chem. Soc. Ethiop. 2024, 38(6), 1703-1713. DOI: https://dx.doi.org/10.4314/bcse.v38i6.16

Ultra-selective hydrogen sensors based on CuO - ZnO hetero-structures grown by surface conversion

Synergistic effects of mixed oxides have the potential to improve sensing performances of environmental, domestic and industrial monitoring devices. However, mixed oxides often come in the form of separate particles and are thus addressed separately by the environment, instead of capitalizing on the interface between the metal oxides. This paper describes a new core@shell gas sensing material of tetrapodal zinc oxide with a surface coating of crystalline copper oxide(t-ZnO@CuO). The special surface conversion strategy yields a unique, self-assembled and pinhole-free coating of CuO nanoplatelets. The morphologies, structural, chemical and gas sensing properties of the heterostructure were investigated. To evaluate the sensing properties of the heterostructure, t-ZnO@CuO was fabricated as nanosensors, consisting of one core-shell rod of CuO-coated crystalline ZnO. The single core@shell rod showed high selectivity towards hydrogen already at comparatively low operation temperatures of 150 °C. Computational calculations based on the density functional theory (DFT) have been carried out to understand the interaction of the H2 gas molecule with the surface of the CuO nanostructures. The surface conversion was done wet chemically and is a novel method for generating heterostructures that can be potentially transferred to heterojunctions with unique properties for chemosensors.

Effect of sandblasting and acid surface pretreatment on the specific capacitance of CuO nanostructures grown by hot water treatment for supercapacitor electrode applications

Crystalline copper oxide (CuO) nanostructures with micro, nano, and micro-nano surface roughness were grown on Cu sheet substrates by a facile, scalable, low-cost, and low-temperature hot water treatment (HWT) method that simply involved immersing Cu sheet in DI water at 75 °C for 24 h without any chemical additives. Various morphological features and sizes of CuO nanostructures were tuned by using different surface pretreatment techniques including acid treatment, sandblasting, or a combination of those two. The surface morphology of the prepared samples was analyzed by scanning electron microscopy. The crystal structure of the CuO nanostructures was investigated by x-ray diffraction XRD and Raman spectroscopy. To study the pseudocapacitive behavior, their potential supercapacitor performance, and equivalent series resistance, electrochemical analysis was done by cyclic voltammetry and electrochemical impedance spectroscopy for all the CuO/Cu samples in 1 M of Na2SO4 electrolyte. Among all, the best supercapacitive performance was achieved for CuO/Cu samples pretreated with Sandblasting followed by Acid treatment resulting in a specific capacitance of about 104 F g−1. The electrode with the sandblasted + acid pretreated sample showed a maximum of ∼69% capacitive retention after 2000 consecutive cycles. Our results indicate that CuO nanostructures on Cu substrates prepared with different surface pretreatment conditions and grown by HWT can be promising electrodes for supercapacitor device applications.

Highly Crystalline Copper Aluminum-Layered Double Hydroxides with Intrinsic Fenton-Like Catalytic Activity for Robust Oral Health Management.

As the main challenge of dental healthcare, oral infectious diseases are highly associated with the colonization of pathogenic microbes. However, current antibacterial treatments in the field of stomatology still lack a facile, safe, and universal approach. Herein, we report the controllable synthesis of copper aluminum-layered double hydroxides (CuAl-LDHs) with high Fenton-like catalytic activity, which can be utilized in the treatment of oral infectious diseases with negligible side effects. Our strategy can efficiently avoid the unwanted doping of other divalent metal ions in the synthesis of Cu-contained LDHs and result in the formation of binary CuAl-LDHs with high crystallinity and purity. Evidenced by experimental and theoretical results, CuAl-LDHs exhibit excellent catalytic ability toward the ·OH generation in the presence of H2O2 and hold strong affinity toward bacteria, endowing them with great catalytic sterilization against both Gram-positive and Gram-negative bacteria. As expected, these CuAl-LDHs provide outstanding treatments for mucosal infection and periodontitis by promoting wound healing and remodeling of the periodontal microenvironment. Moreover, toxicity investigation demonstrates the overall safety. Accordingly, the current study not only provides a convenient and economic strategy for treating oral infectious diseases but also extends the development of novel LDH-based Fenton or Fenton-like antibacterial reagents for further biomedical applications.

Evaluation of structural parameters of monoclinic nanocrystalline CuO and study of sunlight-driven photocatalytic dye degradation, antimicrobial and antioxidant potential

Highly pure, crystalline and spherical-shaped Copper oxide nanoparticles (NPs) have been synthesized via facile chemical coprecipitation. Various models including the Scherrer, Monshi-Scherrer, Williamson-Hall, Size-Strain Plot and Halder-Wagner method have been applied to study the crystal structure characteristics. The lattice parameters associated with the monoclinic crystal lattice of CuO NPs were estimated to be a = 4.69 Å, b = 3.41 Å, c = 5.14 Å and β = 99.87(degree), unit cell volume V = 81.35Å3 and cell density dx = 6.49 g/cm3. The photocatalytic dye degradation proficiency at 20 mg/l CuO concentration and 120 min sunlight exposure results the order of percentage dye degradation Malachite Green (88.4%) > Crystal Violet (70.8%) > Eosin Yellow (70.2%) > Methylene Blue (54.08%) dyes. The antimicrobial activity assessment was done against the broad-spectrum pathogenic microbes unveiled the exceptional microbial controlling capability of CuO NPs. Furthermore, the antioxidant activity test demonstrated the potential free radical scavenging activity of CuO NPs with an IC50 value of 47.733 µg/ml. Highlights Synthesis of pure and spherical shaped nanocrystalline CuO was done by using low cost and facile chemical coprecipitation method. XRD, FTIR, FESEM, EDX, UV-Vis, and Raman spectroscopic techniques were used for characterization purpose. The structural and crystallographic parameters of monoclinic crystal structure of CuO NPs were evaluated successfully. The photocatalytic performance of CuO NPs follow the percentage dye degradation order as MG (88.4%) > CV (70.8%) > EY (70.20%) > MB (54.08%) after 120 minutes of sunlight exposure. CuO NPs exhibit promising antifungal activity against COVID-19 associated Pulmonary Aspergillosis (CAPA) causing pathogenic fung. CuO NPs show potential DPPH free radical scavenging activity with an IC50 value of 47.733 µg/ml.

Green synthesis and characterization of crystalline copper nanoparticles via sodium borohydride reduction towards enhanced gas sensing application

Copper nanoparticles were produced by a chemical reduction method from precursor copper sulphate using sodium borohydride as a reducing agent. Cu nanoparticles were created by the reduction of Cu2+ ions with NaBH4 in an alkaline solution. NaBH4 and CuSO4 have a molar ratio of 1.2 (6:5). CuSO4 has a concentration of 0.02 M, and 0.04 M NaBH4 was added dropwise to develop the precipitate. Further, characterizations were performed by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), Fourier Transform Infrared (FTIR) and Ultraviolet and Visible Spectroscopy (UV–Vis). The synthesis of the pure copper nanoparticles with a cubic crystalline structure was established. The average crystallite size of copper particle size is about 56.73 nm. The values of resistivity of the Cu conductive films were measured 4.1 × 103 Ω cm, 8 0.8 × 10−2 Ω cm and 1.4 × 10−5 Ω cm at different atmospheric environments, including air, nitrogen gas, and hydrogen gas respectively.

Merits of photocatalytic activity of synthesized (ZnxCu(1−x)Fe2O4); x = (0–1) magnetic nanoparticles for wastewater treatment

Synthesis of crystalline zinc copper ferrite nanoparticles was achieved via a simple co-precipitation method. Scanning electron microscope (SEM) is utilized to give the morphological characterization of the prepared samples. A transmission electron microscope (TEM) was employed for further identification and confirmation of the particle size and morphology. Moreover, X-ray diffraction (XRD) and Fourier transformation infrared (FTIR) spectroscopy were utilized to examine crystalline structure and chemical structure, respectively. The photocatalytic performance of Zn0.5Cu0.5Fe2O4 nanoparticles under UV light was assessed by decolorization of methyl orange (MO) azo dye. The efficiency of photocatalytic degradation of 20 ppm of MO by Zn0.5Cu0.5Fe2O4 nanoparticles 15 mg was 96% after 135 min at an ambient temperature of 25 °C and pH value of 3. Further interpretation was carried out and a proposed mechanism for the MO photodegradation over Zn0.5Cu0.5Fe2O4 nanoparticles was suggested.

Slip system level strengthening in nano-indentation of single crystalline copper: Numerical study via a non-local CPFEM model

A three-dimensional non-local crystal plasticity finite element model (CPFEM) integrating the evolution of geometrically necessary dislocations (GNDs) and statistically stored dislocations (SSDs) was developed to simulate the nano-indentation of single crystal copper. The simulation accurately reproduced published experimental results when considering force-depth curves, indentation size effect (ISE), anisotropic plastic deformation and sink-in phenomenon. The accumulated slip, i.e., shear strain in individual slip systems, was quantitively investigated. It is anticipated that the developed non-local CPFEM model can support future sub-micro and nanoscale manufacturing research as it enables the rapid exploration of slip system level mechanical response of a diverse range of crystalline alloys.

Hydrophobic Trinuclear Copper Cluster-Containing Organic Framework for Synergetic Electrocatalytic Synthesis of Amino Acids.

Electrocatalytic synthesis of amino acids provides a promising green and efficient pathway to manufacture the basic substances of life. Herein, reaction of 2,5-perfluroalkyl-terepthalohydrazide and tris(4-µ2 -O-carboxaldehyde-pyrazolato-N, N')-tricopper affords a crystalline trinuclear copper cluster-containing organic framework, named F-Cu3 -OF. Incorporation of abundant hydrophobic perfluroalkyl groups inside the channels of F-Cu3 -OF is revealed to successfully suppress the hydrogen evolution reaction via preventing H+ cation with large polarity from the framework of F-Cu3 -OF and in turn increasing the adsorption of other substrates with relatively small polarity like NO3 - and keto acids on the active sites. The copper atoms with short distance in the trinuclear copper clusters of F-Cu3 -OF enable simultaneous activization of NO3 - and keto acids, facilitating the following synergistic and efficient C─N coupling on the basis of in situ spectroscopic investigations together with theoretical calculation. Combination of these effects leads to efficient electroproduction of various amino acids including glycine, alanine, leucine, valine, and phenylalanine from NO3 - and keto acids with a Faraday efficiency of 42%-71% and a yield of 187-957µmol cm-2 h-1 , representing the thus far best performance. This work shall be helpful for developing economical, eco-friendly, and high-efficiency strategy for the production of amino acids and other life substances.

Evaluation of Antibacterial Activity of Selenium and Copper Oxide Nanoparticles Synthesized by Hibiscus sabdariffa L. Extract

The aim of the present study is to synthesize selenium (SeNPs) and copper oxide (CuONPs) nanoparticles utilizing aqueous extract of Hibiscus sabdariffa L. as a reducing agent. The green synthesized Hibiscus sabdariffa L. selenium and copper oxide nanoparticles were identified by color change. The characterization of SeNPs and CuONPs was achieved by Ultraviolet-visible (UV-VIS) spectroscopy, Field Emission Scanning electron microscope (FESEM), Atomic force microscope (AFM), X-Ray diffraction analysis (XRD) and transform infrared spectroscopy (FTIR). These tests are utilized for detecting stability, morphology, size, crystalline nature and functional groups on nanoparticles surface prepared. The outcomes revealed appearance of the prick-red and green color, indicating a specific color of selenium and copper oxide nanoparticles respectively. It also disclosed that UV-VIS spectroscopy indicated band absorbance at 234 and 274 nanometer of intense surface Plasmon resonance, manifesting the formation and stability of prepared SeNPs and CuONPs. The FESEM image displayed mulit-shapes between spherical and vaulted for selenium and copper oxide nanosized. XRD at 2 theta revealed crystalline selenium and copper oxide nanoparticles, with (54.92-57.79) nm average size. FTIR revealed the presence of functional groups of the plant that act as stabilizing and reducing agents. The antibacterial activity of synthesized nanoparticles was studied against five different bacteria causing food spoilage.

Ficin-copper hybrid nanoflowers with enhanced peroxidase-like activity for colorimetric detection of biothiols.

The proteolytic enzyme ficin exhibits peroxidase-like activity but it is low and insufficient for real applications. Herein, we developed ficin-copper hybrid nanoflowers and demonstrated that they have significantly enhanced peroxidase-like activity of over 6-fold higher than that of free ficin, with one of the lowest Km and highest kcat values among all reported ficin-based peroxidase-like nanozymes. This was most likely caused by the synergistic catalysis of co-existing ficin and crystalline copper phosphate within nanoflower matrices having a large surface area. The nanoflowers were easily prepared by incubating ficin and copper sulfate at ambient temperature, causing coordination interactions between ficin's amine/amide moieties and copper ions, followed by concomitant anisotropic growth of petals composed of copper phosphate crystals with ficin. When compared to free ficin and natural horseradish peroxidase, the resulting nanoflowers' affinity toward H2O2 was greatly increased, yielding Km values of half and one-tenth, respectively, as well as noticeably improved stability. The nanoflowers were then applied to colorimetric determination of biological thiols (biothiols), such as cysteine (Cys), glutathione (GSH), and homocysteine (Hcy), based on their inhibition of nanoflowers' peroxidase-like activity, producing reduced color intensities as the concentration of biothiols increased. This strategy achieved highly sensitive colorimetric determinations of Cys, GSH, and Hcy after only 25-min incubation. Additionally, using this technique, biothiols in human serum were successfully determined with excellent precision, suggesting the potential application of this technology in clinical settings, particularly in point-of-care testing environments.

Synthesis and crystallinity integration of copper nanoparticles by reaction medium

High crystallinity copper nanoparticles are synthesized by a novel simple route at low temperatures under a measurable condition of altering the medium of the reaction. The effect of altering the reaction medium on reducing the surface energy of precursors to form high crystalline copper nanoparticles from their sulphate precursors due to facilities for the capping of nanoparticles is studied in this manuscript. In this observation, copper sulfate pentahydrate (CSP) precursors follow a reduction in the presence of ascorbic acid (reducer) and their crystallinity gradually changes up to 100 % while the CSP medium is water (X), methanol (Y) and water-methanol azeotropic mixture (Z), respectively. XRD identified a pure 100 % metallic copper crystalline phase presence in Y. Exhaustive lattice parameters, peak profiling, lattice constant etc. analysis of the conformation. TGA data ensures the oxidation initiation of pure Cu to CuO at an initial 30 °C, while the calculated activation energy is 27.93 KJ/mol of Y. An outstanding approach in XRD as well as TEM shows that the average size of the particle close to 16 to 78 nm depends on the solvent medium. Furthermore, TEM-couple SAED parallelly proves this consists of miller indices (111), (200) and (220) in X, Y but Z in a single crystal of metallic copper phase for the phenomenon of parallel line diffraction. TEM shows the internal spherical shape of the nanoparticles varies from the medium with the regular arrangement in a uniform distribution that consists of very low agglomeration. EDS confirms highly purified copper nanomaterials in Y is 83 % among the X and Z. The operating process could be applied to synthesize and integrate the crystallinity, particle size and crystal shape of different metallic nanoparticles by alternating the reaction medium.

Hierarchically crystalline copper borate nanosheets as a freestanding electrode for a hybrid supercapacitor

In this study, we have suggested a straightforward approach to fabricating a binder-free electrode of hierarchically crystalline copper borate (Cu-Bi) nanosheets grown on nickel foam using the Successive Ionic Layer Adsorption Reaction (SILAR) method. The best-performing electrode shows a remarkable specific capacitance (Cs) of 2002 Fg−1 at 1 Ag−1 and Cs retention of 85 % for 10,000 GCD cycles. The assembled CB/NF-2//AC device exhibits high cycling stability and achieves a high energy of 52.2 Whkg−1 at a power density of 2622.4 Wkg−1. Remarkably, it reached 152.7 Fg−1 at 2 Ag−1, and the device still has a high capacitance retention of 85 % for 10,000 cycles. This remarkable electrochemical activity could be attributed to: (i) the inherent defects of the prepared electrode via the existence of borates, providing straightforward interaction between the electrolyte and the active species; (ii) designing the hierarchical architecture that could provide a porous nanosheet structure, which generates accessible active sites for quick ion transport, boosting the Cs; (iii) the formation of crystalline Cu-Bi nanosheets, resulting in high stability and superior electrochemical performance compared to the previous amorphous borides; and (iv) the hybridization between the B 2p state and the multiple d-orbitals of transition metals, increasing the electron flow between the atoms. The current work suggests that the growth of hierarchically crystalline Cu-Bi on Ni foam using a low-cost and simple procedure could provide a practical approach to designing hybrid supercapacitors with outstanding electrochemical performance.

Machine Learning Nucleation Collective Variables with Graph Neural Networks.

The efficient calculation of nucleation collective variables (CVs) is one of the main limitations to the application of enhanced sampling methods to the investigation of nucleation processes in realistic environments. Here we discuss the development of a graph-based model for the approximation of nucleation CVs that enables orders-of-magnitude gains in computational efficiency in the on-the-fly evaluation of nucleation CVs. By performing simulations on a nucleating colloidal system mimicking a multistep nucleation process from solution, we assess the model's efficiency in both postprocessing and on-the-fly biasing of nucleation trajectories with pulling, umbrella sampling, and metadynamics simulations. Moreover, we probe and discuss the transferability of graph-based models of nucleation CVs across systems using the model of a CV based on sixth-order Steinhardt parameters trained on a colloidal system to drive the nucleation of crystalline copper from its melt. Our approach is general and potentially transferable to more complex systems as well as to different CVs.

A Comprehensive and Sustainable Recycling Process for Different Types of Blended End-of-Life Solar Panels: Leaching and Recovery of Valuable Base and Precious Metals and/or Elements

The production of photovoltaic modules is increasing to reduce greenhouse gas emissions. However, this results in a significant amount of waste at the end of their lifespan. Therefore, recycling these solar panels is important for environmental and economic reasons. However, collecting and separating crystalline silicon, cadmium telluride, and copper–indium–gallium–selenide panels can be challenging, especially in underdeveloped countries. The innovation in this work is the development of a process to recycle all solar panel waste. The dissolution of all metals through the leaching process is studied as the main step of the flowchart. In the first step of leaching, 98% of silver can be recovered by 0.5 M nitric acid. Then, the second and third step involves the use of glycine for base metal dissolution, followed by the leaching of valuable metals with hydrochloric acid. The effect of parameters such as the initial pH, acid concentration, solid/liquid ratio, and hydrogen peroxide concentration is studied. The results show that up to 100% of Cu, Pb, Sn, Zn, Cd, In, Ga, and Se can be recovered under optimal conditions. The optimal conditions for the dissolution of Cu, Zn, and Cd were a glycine concentration of 0.5 M, a temperature of 25 °C, a solid/liquid ratio of 10 gr/L, and 1% of hydrogen peroxide. The optimized glycine concentration for the leaching of lead and tin was 1.5 M. Indium and gallium were recovered at 100% by the use of 5 M hydrochloric acid, S/L ratio = 10 gr/L, and T = 45 °C. Separation of selenium and tellurium occurred using 0.5 M HCl at a temperature of 60 °C. Additionally, for the first time, a general outlook for the recycling of various end-of-life solar panels is suggested.

The effect of precursor concentration on the crystallinity synchronization of synthesized copper nanoparticles

Highly crystalline copper nanoparticles are formed with Chemical Reduction Method (CRM) by the application of an effective capping agent and changing the precursor concentration. In this study, copper sulphate pentahydrate is used as a precursor which is reduced by ascorbic acid. The synthesized nanoparticles are designated as P, Q and R. These are systematically characterized by X-ray Diffraction (XRD), UV–Visible Spectroscopy (UV), Differential Scanning Calorimetry (DSC), Thermo-gravimetric Analysis (TGA), Transmission Electron Microscope (TEM) coupled with Energy Dispersive X-ray Spectroscopy (EDS). XRD ensured that the crystalline phase gradually changes from 79% to 96% with the change in precursor concentration from 0.08 M to 0.10 M. UV analysis shows that due to the high conductivity of copper nanoparticles might have caused the redshift at 630–634 nm. TGA show the energy of activation (Ea) of P is 22.90 KJ/mol which is more reactive than Q and R. An excellent arrangement in XRD and TEM confirms the average particle size near about 40 nm, with consists of crystal plane (111), (200) and (220). SAED confirmed the particles are elongated with the miller indices of the synthesized nanomaterials on (111), (200) and (220) planes. The EDS confirmed the purity of nanomaterials up to 86%. The adopted process may be employed to synthesize and synchronize the crystallinity of other metal nanoparticles.

Examining the adsorption of gases into solid crystalline molecular copper(II) 3,5-bis(trifluoromethyl)benzoate derivatives

Two copper(II) complexes, both involving the anionic 3,5-bis(trifluoromethyl)benzoate ligand (TFMBz), have been prepared and their structure elucidated by single crystal-X ray diffraction. [Cu(TFMBz)2(ISNA)2] (1) is a mononuclear complex, in which the sphere of coordination of Cu(II) is completed by two neutral isonicotinamide (ISNA) auxiliary ligands. Hydrogen bonding formed between auxiliary ISNA ligands determines the formation of a 2D supramolecular network. [Cu2(TFMBz)4(DMSO)2] (2) is a binuclear complex, in which the four carboxylate ligands define the typical paddle wheel structure often found in copper complexes, containing also the ancillary dimethyl sulfoxide (DMSO) ligand in axial positions. The elucidated crystallographic data provide the static view of the crystal structures, which reveals only non-interconnected voids for both materials. Even that, compound 1 shows an appreciable adsorption of CO2 at 273 K (ca. 1 CO2 molecule/Cu atom at 100 kPa), concomitant with a reduced adsorption of Ar or N2 under similar conditions, which implies a considerable degree of selectivity for CO2. Moreover, 1 does not adsorb N2 or Ar at 77 K and 100 kPa. This behavior suggests that the stablished intermolecular hydrogen bonds rest flexibility and dynamism to 1 at low temperature. Contrarily, increasing the temperature transient porosity is originated, which allows guest molecules to diffuse through the cavities. Compound 2 shows adsorption of N2 and Ar at 77 K, indicating that vibrations in the network and rotation of some CF3 groups, necessary to favor adsorbate diffusion, are still feasible at this low temperature.

Enhancement of Dopamine Electrochemical Detection with Manganese Doped Crystalline Copper Oxide

Manganese doped crystalline copper oxide (CuO:Mn) and undoped CuO were prepared at room temperature by the hydrothermal method. The complete physico-chemical characterization of the materials was performed using X-ray diffraction (XRD), transmission/scanning electron microscopy (TEM/SEM), and X-ray photoelectron spectroscopy (XPS). Furthermore, their analytical applicability was tested in electrochemical experiments for a dopamine assay. According to the morphological investigation, the materials had a flat structure with nearly straight edges. The XRD analysis proved the formation of the CuO phase with good crystallinity, while the Mn doping was determined by XPS to be around 1 at.%. Under optimized conditions, at pH 5.0, the CuO:Mn modified electrode (CuO:Mn/SPE) showed a high signal for dopamine oxidation, with a linear response in the 0.1–1 µM and 1–100 µM ranges and a low limit of detection of 30.3 nM. Five times higher sensitivity for manganese doped copper oxide in comparison with the undoped sample was achieved. The applicability of the developed CuO:Mn/SPE electrode was also tested in a commercially available pharmaceutical drug with good results, suggesting that the developed sensor has promising biomedical application potential.