Copper Hydroxide Acetate Research Articles

Self-sacrificing template fabrication of mesoporous CuO micro/nanoplates for photo-Fenton-like oxidation of sulfathiazole

In this study, we offer a simple self-sacrificial template-directed method to prepare mesoporous CuO micro/nanoplates by using copper hydroxide acetate (Cu2(OH)3(CH3COO)·H2O) plates as a template. The as-prepared material was structurally, morphologically, optically and texturally characterized and its excellent catalytic activity in the LED-driven photo-Fenton-like process of sulfathiazole oxidation was demonstrated. Within 90 min, 100 % sulfathiazole degradation and 87.3 % TOC removal were achieved in the presence of H2O2 and visible LED irradiation. Moreover, the degradation of sulfathiazole can still reach 96.1 % after five cycles, which indicates exceptional performance of the catalyst.

Antibacterial Carbon Nanotubes by Impregnation with Copper Nanostructures

The addition of metal-based nanoparticles on carbon nanotubes (CNT) is a relevant method producing multifunctional materials. In this context, CNT were dispersed in an ethanol/water solution containing copper acetate for their impregnation with different copper nanostructures by either a non-thermal or a thermal post-synthesis treatment. Our simple method is based on pure CNT in an air atmosphere without any other reagents. Particles without thermal treatment were present as a well-dispersed layered copper hydroxide acetate nanostructures on CNT, as confirmed by scanning and transmission (TEM) electron microscopies, and showing a characteristic x-ray diffraction peak at 6.6°. On the other hand, by thermal post-synthesis treatment at 300°C, these layered nanostructures became Cu2O nanoparticles of around 20 nm supported on CNT, as confirmed by TEM images and x-ray diffraction peaks. These copper nanostructures present on the CNT surface rendered antibacterial behavior to the resulting hybrid materials against both Staphylococcus aureus and Escherichia coli. These findings present for the first time a simple method for producing antibacterial CNT by direct impregnation of copper nanostructures.

The role of 2D/3D spin-polarization interactions in hybrid copper hydroxide acetate: new insights from first-principles molecular dynamics.

The magnetic properties response of the layered hybrid material copper hydroxide acetate Cu2(OH)3CH3COO·H2O is studied as a function of the applied pressure within first-principles molecular dynamics. We are able to elucidate the interplay between the structural properties of this material and its magnetic character, both at the local (atomic) level and at the bulk level. We performed a detailed analysis of the intralayer spin configurations occurring for each value of the imposed projection along the z-axis for the total spin and of the applied pressure. The transition from an antiferromagnetic to a ferromagnetic state at high pressure (above 3 GPa) goes along with a vanishing difference between the spin polarizations pertaining to each layer. Therefore, at high pressure, copper hydroxide acetate is a ferromagnet with no changes of spin polarization in the direction perpendicular to the inorganic layers.

Magnetic Materials: Structure and Magnetic Property Control of Copper Hydroxide Acetate by Non‐Classical Crystallization (Small 9/2017)

A method for synthesizing inorganicorganic composite materials with tunable magnetic properties is developed by using copperincorporated block copolymer micelles as precursors in combination with ultracentrifugation induced crystallization. In article number 1602702, H. Cölfen and co-workers show that magnetic properties of these materials can be controlled by varying polymer microstructures that change the structures of copper hydroxide acetate.

Structure and Magnetic Property Control of Copper Hydroxide Acetate by Non-Classical Crystallization.

Copper hydroxide acetate (CHA), one layered hydroxide compound with tunable magnetism, attracts great interest because of its potential applications in memory devices. However, ferromagnetism for CHA is only demonstrated by means of GPa pressure. Herein, a new method is reported, involving the combination of different crystallization pathways to control crystallization of amorphous CHA toward the formation of CHA/polymer composites with tunable magnetic properties and even a tunability that can be tested at room temperature. By using poly[(ethylene glycol)6 methyl ether methacrylate]-block-poly[2-(acetoacetoxy) ethyl methacrylate] (PEGMA-b-PAEMA) diblock copolymers as additives in combination with a post-treatment process by ultracentrifugation, it is demonstrated that CHA and PEGMA-b-PAEMA form composites exhibiting different magnetic properties, depending on CHA in-plane nanostructures. Analytical characterization reveals that crystallization of CHA is induced by ultracentrifugation, during which CHA nanostructures can be well controlled by changing the degrees of polymerization of the PEGMA and PAEMA blocks and their block length ratios. These findings not only present the first example of using crystallization from polymer stabilized amorphous precursors toward the generation of magnetic nanomaterials with tunable magnetism but also pave the way for the future design of functional composite materials.

Pseudomorphic Transformation of Layered Simple Hydroxides into Prussian Blue Analogue Nanoplatelets

AbstractThe reactivity of potassium or sodium hexacyanoferrate(II) with transition‐metal layered simple hydroxides (LSHs) has been investigated to evaluate the possibility of inserting Prussian Blue analogues (PBAs) into magnetic copper(II) LSHs. This report shows how such a reaction led, unexpectedly, to the direct formation of PBA nanoparticles, the layered hydroxide serving as a metal‐ion reservoir. The lamellar structure of the starting LSH collapses and copper–iron PBA nanoparticles were obtained as well‐defined cubic structures stacked in layers. In addition to structural and magnetic characterization, the reaction mechanism was investigated by 57Fe Mössbauer spectrometry and X‐ray photoemission spectroscopy. The layered copper hydroxide acetate turns out to be a smart precursor of well‐shaped PBA nanoparticle layers through pseudomorphic replication.

Facile synthesis of CuO nanosheets via the controlled delamination of layered copper hydroxide acetate

CuO nanosheets were prepared by the controlled delamination of layered copper hydroxide acetate followed by the in situ solvothermal transformation of hydroxide to oxide. The reaction was performed in 1-butanol in order to prevent recrystallization or nanoparticle aggregation. Analyses by small angle X-ray scattering, transmission electron microscopy, and atomic force microscopy revealed that the CuO nanosheets are approximately 1nm thin, corresponding to three to four stacked CuO6 octahedral layers. The average lateral size is approximately 5nm. The nanosheets form stable dispersions in 1-butanol that are suitable for the fabrication of transparent and homogeneous CuO thin films by spin-coating or inkjet printing techniques. The present synthesis is a rare example of the top down strategy leading to the nanometric two-dimensional nanosheets of non-layered oxide materials.

Facile synthesis of porous copper oxide nanostructure using copper hydroxide acetate precursor

Porous copper oxide nanostructures were synthesized by thermal decomposition of copper hydroxide acetate precursor. The precursor synthesized by a facile solution phase method presents a flower-like configuration, assembled from plate-like structures. CuO with porous features were obtained via thermal decomposition of the precursor, but morphology remains unchanged after the conversion. Under laser light irradiation, copper hydroxide acetate displays a phase transition to CuO as observed by the power dependent Raman spectroscopy.

Tuning Magnetic Properties with Pressure in Hybrid Organic–Inorganic Materials: The Case of Copper Hydroxide Acetate

The magnetic response and related spin topology of the hybrid organic–inorganic material copper hydroxide acetate Cu2(OH)3(CH3COO)·H2O are studied as a function of an applied external pressure within first-principles approaches. We show that structural changes induced by high pressure affect the Cu–O–Cu angles, particularly when the bridging O atom belongs to the CH3COO chains, with a sharp transition occurring above 2.75 GPa. These geometrical modifications are responsible for a transition from an antiferromagnetic (at the ambient pressure ground state) to a ferromagnetic state at high pressure (∼7 GPa). Our results are in agreement with the experimental outcome. They provide a guideline for applications of these composite systems in nanoelectronics and disclose new frontiers in the design of memory devices based on this family of hybrid lamellar materials.

ChemInform Abstract: Synthesis and Characterization of Single Crystals of the Layered Copper Hydroxide Acetate Cu2(OH)3(CH3COO)·H2O.

AbstractSingle crystals of the title compound are obtained from an aqueous solutions of Cu(OAc)2 (60 °C, 30 h) and the crystal structure is determined by single crystal XRD.

First principles investigation of the atomic structure and magnetic properties of copper hydroxide acetate

Abstract Within the density functional theory (DFT) framework, we study the structural properties and the spin density distribution of copper hydroxide acetate Cu2(OH)3(CH3COO)·H2O, a fundamental compound in the field of hybrid organic-inorganic materials. In particular, after a careful comparison of the computed structure with the experimentally obtained X-ray pattern, we provide an insight into the effect of two exchange-correlation functionals (BLYP and HCTH/120) on the description of the magnetic properties and on the related changes in the atomic structure. Since these compounds are known to possess a piezomagnetic character, for the total spin value S = 0 and S = 4, we inspect at different pressures, and for each one of the two exchange-correlation functionals, the changes in the geometry and in the spin density distribution. We notice that, at total spin density S = 0, and for both the external pressures of 3 and 5 GPa, most of the local spin densities are due to dyz orbitals with about 25% contribution from dz2 orbitals. Such a feature is insensitive to the exchange-correlation functional adopted. Overall, our results provide an important first step towards the comprehension of the effects of an external stress on the magnetic properties of this class of hybrid materials.

Synthesis and characterization of single crystals of the layered copper hydroxide acetate Cu2(OH)3(CH3COO)·H2O

AbstractSingle‐crystals of the layered copper hydroxide acetate Cu2(OH)3(CH3COO)·H2O were synthesized by heating copper acetate solution at 60 °C. The standard synthesis of the title compound based on slow titration of copper acetate solution with NaOH yielded materials with worse morphology and an additional phase present. The obtained products were characterized with powder X‐ray diffraction, high temperature powder X‐ray diffraction, scanning electron microscopy and infrared spectroscopy. The crystal structure was determined from single‐crystal X‐ray diffraction data, collected both at 120 K and at 293 K. The title compound crystallizes in the monoclinic botallackite‐type layered structure, space group P 21, with the lattice parameters a = 5.5776(3) Å, b = 6.0733(2) Å, c = 18.5134(8) Å, β = 91.802(4)° and a = 5.5875(4)Å, b = 6.0987(4) Å, c = 18.6801(10)Å, β = 91.934(5)° for 120 K and for 293 K, respectively. Acetate groups and water molecules are interlayered between corrugated sheets of edge‐sharing CuO6 octahedra exhibiting strong distortion resulted from the Jahn‐Teller effect. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Atomic Structure and Magnetic Nature of Copper Hydroxide Acetate

By using density-functional theory in the framework of first-principles molecular dynamics, we carry out a dynamical annealing to identify the stable structures of copper hydroxide acetate Cu2(OH)3(CH3COO)·H2O, a fundamental compound in the field of hybrid organic−inorganic materials, for which accurate crystallographic data are not available. For the total spin value S = 0, we obtain a large set of stable structures having very close sets of coordinates and differing in the spatial distribution of the spin densities. Only some of these structures (∼20%) feature spin topologies consistent with the in-plane ferromagnetic character experimentally established. An electron localization analysis through the electron localization function ELF shows that the different atomic and molecular units composing the systems (Cu2(OH)3(CH3COO)−, OH− and H2O) can be associated with different localization basins and connect to each other through noncovalent interactions. The relationship between the appearance of sizable spin densities on specific O atoms and the magnitude of the spin densities on the neighboring Cu atoms is also discussed.

Characterization of Vapor Phase Copper Corrosion Products Using Electrochemical Methods

The copper corrosion products originated by the action of formic, acetic and propionic acid vapors at a 100% relative humidity were studied for a period of 21 days. Five formic, acetic and propionic vapor concentrations (10, 50, 100, 200 and 300 ppm) were tested. The corrosion-product layers were characterized using electrochemical methods. Some of the compounds identified were: cuprite (Cu2O), for the three acids; cupric hydroxide monohydrate (Cu(OH)2•H2O) and copper formate tetrahydrate (Cu(HCOO)2•4H2O), for formic acid; copper acetate dihydrate (Cu(CH3COO)2•2H2O) and copper hydroxide acetate dihydrate (Cu4(OH)(CH3COO)7•2H2O), for acetic acid; and copper propionate (Cu4(OH)(CH3CH2COO)7•2H2O) for propionic acid.

Synthesis and characterization of nickel–copper hydroxide acetate, NiCu(OH) 3.1(OCOCH 3) 0.9 · 0.9H 2O

Nickel–copper hydroxide acetate with a chemical composition of NiCu(OH) 3.1(OCOCH 3) 0.9 · 0.9H 2O was synthesized by hydrothermal heating of an aqueous solution containing nickel acetate, copper acetate, and hydrogen peroxide to 423 K for 4 h. The crystal structure of this compound can be described as brucite-type octahedral (Ni,Cu)(OH) 2 layers, where a part of OH sites are replaced by acetate ions located in the interlayer. This compound is stable below about 455 K except that the reversible dissociation and association of the water molecules from/with the interlayer acetate ions occur depending upon the surrounding conditions. Above 455 K, a part of the interlayer acetate ions are released from the solid phase. The solid phase is decomposed to nickel and copper oxides above about 500 K. The synthesized nickel–copper hydroxide acetate takes up little or no Cl − and NO 3 - but shows high selectivity for multivalent anions such as SeO 3 2 - and AsO 4 3 - . The uptake of multivalent anions proceeds on the basis of exchange with the acetate ions but may also involve exchange with the hydroxide ions in the matrix hydroxide layers.

Synthesis and Characterization of Copper Hydroxide Acetate With a Layered Discoid Crystal

Titration of copper acetate solution with a dilute NaOH solution to pH 6.5 and subsequent aging at 313 K yielded copper hydroxide acetate with an analytical composition of Cu2(OH)3.1(OCOCH3)0.9nH2O (n ∼ 0.7) and layered discoid crystals. The chemical composition, structure, and holistic trend in thermal behavior are similar to those of the previously known Cu2(OH)3(OCOCH3)H2O phase with layered rectangular crystals. The most obvious difference between the two compounds is morphology of the crystals. The other major differences are found in stability of bonding of the interlayer acetate ions to solid phase and behavior in anion-containing solutions. The interlayer acetate ions in the present compound begin to be dissociated from the solid phase at ∼343 K while those in the previous compound are not dissociated below 383 K. The reaction of the present compound is topotactic in Cl− and NO3− aqueous solutions but reconstructive in a SO42− aqueous solution while the reaction of the previous compound in those solutions is topotactic.

Modification of the Interlayer Surface of Layered Copper(II) Hydroxide Acetate with Benzoate Groups: Submicrometer Fiber Generation

We report on the functionalization of layered copper(II) hydroxide acetate with benzoic acid. The grafting of benzoate groups is characterized by thermogravimetry/differential scanning calorimetry, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The submicrometer fiber generation of the grafted material is clearly demonstrated through scanning electron microscopy.

A comparative study on copper corrosion originated by formic and acetic acid vapours

The copper corrosion rate and products originated by the action of formic and acetic acid vapours at a 100% relative humidity were studied. Copper specimens were exposed to formic and acetic acid vapours for a period of 21 days. Five formic and acetic acid vapour concentrations (10, 50, 100, 200 and 300 ppm) were tested. Copper corrosion rates of up to 1300 mg m−2 d−1 (mmd) for formic acid and up to 2300 mmd for acetic acid were measured using a gravimetric method. The corrosion-product layers were characterised using electrochemical, X-ray powder diffraction and scanning electron microscopy techniques. Some of the compounds identified were: cuprite (Cu2O), for both acids; cupric hydroxide monohydrate (Cu(OH)2 · H2O) and copper formate tetrahydrate (Cu(HCOO)2 · 4H2O), for formic acid; and copper acetate dihydrate (Cu(CH3COO)2 · 2H2O) and copper hydroxide acetate dihydrate (Cu4(OH)(CH3COO)7 · 2H2O), for acetic acid.

A Laboratory Study of the Effect of Acetic Acid Vapor on Atmospheric Copper Corrosion

A study was made of the copper corrosion rate and corrosion products originated by the action of acetic acid vapor at 100% relative humidity. Copper plates were exposed to an acetic acid contaminated atmosphere for a period of 21 days. Five acetic vapor concentration levels were used. The copper corrosion rate was in the range of 1 to 23 mg/dm2 day. The corrosion‐product layers were characterized using electrochemical, X‐ray powder diffraction, Fourier transform infrared spectrometry, and scanning electron microscopy techniques. Thermal and calorimetric studies were also performed. Some of the compounds identified were cuprite , copper acetate hydrate , and copper hydroxide acetate . This last compound was also characterized. The thickness of the patina layers was 4 to 8 nm for amorphous cuprite, 11 to 48 nm for cuprite, and 225 nm for copper acetate. The patina, in which the cementation process of different corrosion‐product layers plays an important role, is formed by the reaction of acetic vapor with copper through porous cuprite paths.