Facile synthesis of Cu-doped manganese oxide octahedral molecular sieve for the efficient degradation of sulfamethoxazole via peroxymonosulfate activation

Advanced processes for peroxymonosulfate(PMS)-based oxidation are efficient in eliminating toxic and refractory organic pol-lutants from sewage.The activation of electron-withdrawing HSO_(5)^(-)releases reactive species,including sulfate radical(·SO_(4)^(-)),hydroxyl radical(·OH),superoxide radical(·O_(2)^(-)),and singlet oxygen(1O_(2)),which can induce the degradation of organic contaminants.In this work,we synthesized a variety of M-OMS-2 nanorods(M=Co,Ni,Cu,Fe)by doping Co^(2+),Ni^(2+),Cu^(2+),or Fe^(3+)into manganese oxide oc-tahedral molecular sieve(OMS-2)to efficiently remove sulfamethoxazole(SMX)via PMS activation.The catalytic performance of M-OMS-2 in SMX elimination via PMS activation was assessed.The nanorods obtained in decreasing order of SMX removal rate were Cu-OMS-2(96.40%),Co-OMS-2(88.00%),Ni-OMS-2(87.20%),Fe-OMS-2(35.00%),and OMS-2(33.50%).Then,the kinetics and struc-ture-activity relationship of the M-OMS-2 nanorods during the elimination of SMX were investigated.The feasible mechanism underly-ing SMX degradation by the Cu-OMS-2/PMS system was further investigated with a quenching experiment,high-resolution mass spec-troscopy,and electron paramagnetic resonance.Results showed that SMX degradation efficiency was enhanced in seawater and tap water,demonstrating the potential application of Cu-OMS-2/PMS system in sewage treatment.

Nitric oxide removal from flue gas coupled with the Fe^(Ⅱ)EDTA regeneration by ultraviolet irradiation

During wet complexation denitrification of flue gas,Fe^(Ⅱ)EDTA regeneration,also known as reducing Fe^(Ⅱ)EDTA and Fe^(Ⅱ)EDTA-nitric oxide(NO)to Fe^(Ⅱ)EDTA,is crucial.In this paper,ultraviolet(UV)light was used for the first time to reduce Fe^(Ⅱ)EDTA-NO.The experimental result demonstrated that Fe^(Ⅱ)EDTA-NO reduction rate increased with UV power increasing,elevated temperature,and initial Fe^(Ⅱ)EDTA-NO concentration decreasing.Fe^(Ⅱ)EDTA-NO reduction rate increased first and then decreased as pH value increased(2.0-10.0).Fe^(Ⅱ)EDTA-NO reduction with UV irradiation presented a first order reaction with respect to Fe^(Ⅱ)EDTA-NO.Compared with other Fe^(Ⅱ)EDTA regeneration methods,Fe^(Ⅱ)EDTA regeneration with UV show more superiority through comprehensive consideration of regeneration rate and procedure.Subsequently,NO absorption experiment by Fe^(Ⅱ)EDTA solution with UV irradiation confirmed that UV can significantly promote the NO removal performance of Fe^(Ⅱ)EDTA.Appropriate oxygen concentration(3%(vol))and acidic environment(pH=4)was favorable for NO removal.With UV power increasing as well as temperature decreasing,NO removal efficiency rose.In addition,the mechanism research indicates that NO from flue gas is mostly converted to NO_(2)-,NO_(3)-,NH_(4)^(+),N_(2),and N_(2)O with Fe^(Ⅱ)EDTA absorption liquid with UV irradiation.UV strengthens NO removal in Fe^(Ⅱ)EDTA absorption liquid by forming a synergistic effect of oxidation-reduction-complexation.Finally,compared with NO removal methods with Fe^(Ⅱ)EDTA,Fe^(Ⅱ)EDTA combined UV system shows prominent technology advantage in terms of economy and secondary pollution.

A core-shell copper oxides-cobalt oxides heterostructure nanowire arrays for nitrate reduction to ammonia with high yield rate

Electrochemical nitrate reduction to ammonia(NRA) can realize the green synthesis of ammonia(NH3) at ambient conditions, and also remove nitrate contamination in water. However, the current catalysts for NRA still face relatively low NH3yield rate and poor stability. We present here a core-shell heterostructure comprising cobalt oxide anchored on copper oxide nanowire arrays(CuO NWAs@Co_(3)O_(4)) for efficient NRA. The CuO NWAs@Co_(3)O_(4)demonstrates significantly enhanced NRA performance in alkaline media in comparison with plain CuO NWAs and Co_(3)O_(4)flocs. Especially, at-0.23 V vs. RHE, NH_(3) yield rate of the CuO NWAs@Co_(3)O_(4)reaches 1.915 mmol h^(-1)cm^(-2),much higher than those of CuO NWAs(1.472 mmol h^(-1)cm^(-2)), Co_(3)O_(4)flocs(1.222 mmol h^(-1)cm^(-2)) and recent reported Cu-based catalysts.It is proposed that the synergetic effects of the heterostructure combing atom hydrogen adsorption and nitrate reduction lead to the enhanced NRA performance.

Environmentally Friendly Room Temperature Synthesis of 1-Tetralone over Layered Double Hydroxide-Hosted Sulphonato-Salen-Nickel(II) Complex

1-Tetralone, a useful synthetic intermediate in the manufacture of pharmaceuticals, agrochemicals and dyes, can be prepared by liquid phase catalytic oxidation of tetralin. Selective oxidation of tetralin to 1-tetralone is still a big challenge with low-temperature processes using environmentally friendly routes even after decades of research. Herein, we demonstrate room-temperature oxidation of tetralin to 1-tetralone over layered double hydroxide-hosted sulphonato-salen-nickel(II) complex, LDH-[Ni-salen]. The layered double hydroxide-hosted sulphonato-salen-nickel(II) compound was characterized by powder X-ray diffraction, Fourier transform infrared spectrometer (FTIR), UV-Visible diffuse reflectance spectra, scanning electron microscopy (SEM) and elemental analysis. The theoretical calculations of free sulphonato-salen-nickel(II) complex using Density Functional Theory/CAM-B3LYP at the 6-311++ G(d,p) level of theory were also used to determine the orientation of the Ni-salen compound within the layered structure. The immobilized compound, LDH-[Ni-salen] was found to be an effective reusable catalyst for the oxidation of tetralin to 1-tetralone using a combination of trimethylacetaldehyde and molecular oxygen (14.5 psi) and at 25°C. At 45.5% conversion, tetralin was converted to 1-tetralone with 77.2% selectivity at room temperature and atmospheric pressure after 24 h. The catalyst recycles test and hot filtration experiment showed that oxidation proceeded through Ni(II) sites in LDH-[Ni-salen]. The catalysts were reused several times without losing their catalytic activity and selectivity. The present results may provide a convenient strategy for the preparation of 1-tetralone using layered double hydroxide-based heterogeneous catalyst at ambient temperature for industrial application in near future.

The Antibacterial Activities of Copper Oxide Nanoparticles Synthesized Using Laser Ablation in Different Surfactants against Streptococcus mutans

Copper oxide nanoparticles(CuO NPs)were synthesised with laser ablation of a copper sheet immersed in deionized water(DW),cetrimonium bromide(CTAB),and sodium dodecyl sulphate(SDS),respectively.The target was irradiated with a pulsed Nd:YAG laser at 1064 nm,600 mJ,a pulse duration of 10 ns,and a repetition rate of 5 Hz.The CuO NPs colloidal were analyzed using UV–Vis spectroscopy,the Fourier transform infrared(FTIR)spectrometer,zeta potential(ZP),X-ray diffraction(XRD),transmission electron microscope(TEM)and field emission scanning electron microscopy(FESEM).The absorption spectra of CuO NPs colloidal showed peaks at 214,215 and 220 nm and low-intensity peaks at 645,650 and 680 nm for SDS,CTAB and DW,respectively.CuO NPs’colloidal results are(−21.6,1.2,and 80 mV)for negatively,neutrally,and positively charged SDS,DW,and CTAB,respectively.The XRD pattern of the NPs revealed the presence of CuO phase planes(110)(111),(20-2)and(11-1).The TEM images revealed nearly spherical NPs,with sizes ranging from 10–90,10–50,and 10–210 nm for CuO NPs mixed with DW,SDS and CTAB,respectively.FESEM images of all the synthesized samples illustrate the formation of spherical nanostructure and large particles are observable.The CuO NPs were tested for antibacterial activity against Streptococcus mutans by using the well diffusion method.In this method,CuO NPs prepared in DW at a concentration of 200μg/mL showed a greater inhibition zone against Streptococcus mutans.

Synthesis and Structure of bis(μ-2-aminopyridine N-oxide)-bis[dichlorocopper(II)]

The complex [Cu2（apo）4Cl4]·2H2O （apo=2-aminopyridine N-oxide） was obtained. A single- crystal X-ray study shows that the complex is a binuclear compound （Cu2C20H28Cl4N8O6）. The coordination geometry about each copper atom is best described as a distorted square pyramid. The compound [Cu2（apo）4Cl4]·2H2O belongs to the triclinic system with space group P, lattice constants: a = 7.8550（7）, b = 8.5378（7）, c = 12.082（1） ?, α = 72.807（1）, β = 77.641（1）, γ = 70.800（1）(, V =724.85（11） ?3, Z=1, Mr =745.38, Dc=1.708 g/cm3, μ =1.886mm-1, F（000） =378, R=0.0359, wR2=0.0884 for 2220 reflections with I >2σ（I）. The distances between Cu（II） and O atoms are in the range from 1.934（2） to 2.042（2）?. The distance between two copper atoms Cu-Cu（A） is 3.2978（8） ?. The distances of Cu-Cl（1） and Cu-Cl（2） are 2.2322（9）, 2.5095（10） ?, respectively. There is no evident hydrogen bond between N and Cl.

Preparation, Characterization, and Application of Manganese Oxide Coated Zeolite as Adsorbent for Removal of Copper(II) Ions from Seawater

The present study is aimed to examine the adsorption characteristics of Cu(II) by using the novel cellulose acetate composite and to apply it for the removal of Cu(II) from real wastewater samples. In order to achieve this objective, ethylenediamine, diethylenetriamine, triethylenetetramine and te-traethylenepentanene were used for immobilization of grafted cellulose acetate-nanoscale manganese dioxide. Cellulose was extracted from mangrove species Avicennia marina and converted to cellulose acetate then it was formed composite with nano-manganese dioxide via precipitation of nano-manganese dioxide on it. The composite was grafted with acrylamide monomer before immobilization. The synthesized compounds were used for adsorption of Cu(II) and characterized by FT-IR, TGA and SEM. The adsorption characteristics of synthesized sorbents were optimized. Langmuir and Freundlich models were used to establish sorption equilibria. The analytical applications of these modified materials were applied successfully for the removal of Cu(II).

A NOVEL SYNTHETIC METHOD AND STRUCTURE OF TETRAKIS(BENZOATE)BIS(TRIPHENYLPHOSPHINE OXIDE)DICOPPER(II).OXIDATIVE ADDITION OF DIBENZOYL ON METALLIC COPPER

Dibenzoyl peroxide undergoes oxidative addition on metallic copper with triphenylphosphine in a mixed solvent(acetone,dichloromethane and trichloromethane),and affords the binuclear copper complex (Cu(C_6H_5COO)_2(OPPh_3))_2.Crystals are monoclinic,space group A_2/a,with cell parameters,a=24.337(3),b=10.566(1),c=21.579(2),β= 93.18(1)°, V=5540(1)~3,Z=4,R=0.042,and Rw=0.044 for 5872 observed reflections. Each copper ion is coordinated by four bridging benzoato ligands and one triphenylphosphine oxide group to form binuclear complexes.

Synthesis of Multifunctionalised 2-Substituted Benzimidazoles Using Copper (II) Hydroxide as Efficient Solid Catalyst

Here we demonstrate the synthesis of multifunctionalised benzimidazoles through the coupling of o-phenylenediamine with aldehydes by using Copper (II) hydroxide as an efficient solid catalyst in methanol at room temperature. The Copper (II) hydroxide solid catalyst gave better yields (80%-99%) in short reaction time (4-8 h). These commercially available cheap catalysts are more active than many reported expensive heterogeneous catalysts. Using the Copper hydroxide fresh catalyst, the yield of product 3a was 98%, while the recovered catalyst in the three subsequent cycles gave the yield of 94%, 90% and 88% respectively.

Dispersion of copper oxide supported on γ-alumina and its sulfation properties

CuO/γ-Al2O3 catalysts were prepared by impregnation with different CuO loadings. The dispersion of CuO supported on γ-Al2O3 support was studied using X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and temperature programmed reduction （TPR）. The dispersion threshold of CuO in γ-Al2O3 determined by X-ray quantitative analysis was 0.275 g/g, i.e., 0.275CuAl. Highly dispersed CuO or crystalline CuO would appear on the γ-Al2O3 support when CuO loading was below or more than its dispersion threshold. TPR experiments show that reduction peak temperature ranges of 0.1CuAl and pure CuO are 420-690 °C and 290-380 °C, respectively. 0.1CuAl is not easily reduced due to interaction between CuO and γ-Al2O3. 0.5CuAl shows a two-step reduction range during 210-300 °C and 410-730 °C, which confirms the existence of highly dispersed CuO and crystalline CuO. The sulfation experiments show the optimal CuO loading amount is far below its dispersion threshold, and copper oxide supported on γ-Al2O3 is in the form of submonolayer.

Carbon monoxide oxidation on copper manganese oxides prepared by selective etching with ammonia

A series of copper manganese oxides were prepared using a selective etching technique with various amounts of ammonia added during the co-precipitation process. The effect of the ammonia etching on the structure and catalytic properties of the copper manganese oxides was investigated using elemental analysis, nitrogen physisorption, X-ray powder diffraction, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, H2 temperature-programmed reduc- tion, and Oz temperature-programmed desorption combined with catalytic oxidation of CO. It was found that ammonia can selectively remove copper species from the copper manganese oxides, which correspondingly generates more defects in these oxides. An oxygen spillover from the man- ganese to the copper species was observed by H2 temperature-programmed desorption, indicating that ammonia etching enhanced the mobility of lattice oxygen species in these oxides. The Oz tem- perature-programmed desorption measurements further revealed that ammonia etching improved the ability of these oxides to release lattice oxygen. The improvement in redox properties of the copper manganese oxides following ammonia etching was associated with enhanced catalytic performance for CO oxidation.

Catalytic epoxidation of olefin over supramolecular compounds of molybdenum oxide clusters and a copper complex

The catalytic epoxidation of olefin was investigated on two copper complex-modified molybdenum oxides with a 3D supramolecular structure, [Cu（bipy）]4[Mo15O47].2H2O （1） and [Cu1（bix）][（Cu1bix） （δ-MoVl8O26）0.5] （2） （bipy = 4,4＇-bipyridine, bix = 1,4-bis（imidazole-1-ylmethyl）benzene）. Both compounds were catalytically active and stable for the epoxidation of cyclooctene, 1-octene, and styrene with tert-butyl hydroperoxide （t-BuOOH） as oxidant. The excellent catalytic performance was attributed to the presence of stable coordination bonds between the molybdenum oxide and copper complex, which resulted in the formation of easily accessible Mo species with high electropositivity. In addition, the copper complex also acted as an active site for the activation of t-BuOOH, thus im- proving these copper complex-modified polyoxometalates.

Effect of Precipitation Method and Ce Doping on the Catalytic Activity of Copper Manganese Oxide Catalysts for CO Oxidation

The influence of Ce doping and the precipitation method on structural properties and the catalytic activity of copper manganese oxides for CO oxidation at ambient temperature have been investigated. The catalysts were characterized by means of the powder X-ray diffraction and N2 adsorption-desorption, the inductively coupled plasma atomic emission spectrometry, the temperature programmed reduction, diffuse reflectance UV-Vis spectra, and the X-ray photoelectron spectroscopy. It was found that after doping little amount of Ce in copper manganese oxide, CeO2 phase was highly dispersed and could prevent sintering and aggregating of the catalyst, the size of the catalytic material was decreased, the reducibility was enhanced, the specific surface area was increased and the formation of the active sites for the oxidation of CO was improved significantly. Therefore, the activity of the rare earth promoted catalyst was enhanced remarkably.

Synthesis and characterization of porous cobalt oxide/copper oxide nanoplate as novel electrode material for supercapacitors

A promising Co3O4/Cu O composite electrode material was successfully synthesized through a facile hydrothermal and calcination process. Effects of the surfactants hexadecyltrimethyl ammonium bromide（CTAB） and polyvinylpyrrolidone（PVP） on the morphology and electrochemical performance of the composite were investigated. Powder X-ray diffraction（XRD）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM） and nitrogen adsorption-desorption experiment were employed to characterize the microstructures and morphologies of the composite. Meanwhile, the electrochemical performances of the samples were studied using cyclic voltammetry（CV）, galvanostatic charge-discharge test and electrochemical impedance spectroscopy（EIS）. The results show that the porous Co3O4/Cu O-CTAB nanoplates own the best performance and exhibits a high specific capacitance of 398 F/g at 1 A/g with almost 100% capacitance retention over 2000 cycles, and it retains 90% of capacitance at 10 A/g.

Mechanism and application on sulphidizing flotation of copper oxide with combined collectors

The effect of sodium butyl xanthate (NaBX) and dodecylamine (DDA) as combined collector on the sulphidizing flotation of copper oxide was investigated by flotation test, fluorescent pyrene probe, zeta potential, and infrared spectroscopy analyses. The micro-flotation results show that combined use of NaBX+DDA yields better effect than using NaBX at pH 7-11 only, and the optimal molar ratio of NaBX to DDA is 2: 1. The actual ores flotation shows that when the dosage of NaBX+DDA is (100+54) g/t, the copper concentrate grade and recovery are 15.93% and 76.73%, respectively. The fluorescent pyrene probe test demonstrates that the NaBX+DDA can reduce the micelle concentration in the pulp. The zeta potential and the infrared spectroscopy analyses indicate that chemical adsorption, hydrogen-bonding and electrostatic interaction can help to adsorb NaBX+DDA on the surface of malachite. Meantime, copper xanthate and copper-amine complexes may be generated during the adsorption process.

Technological conditions and kinetics of leaching copper from complex copper oxide ore

The kinetic behavior of leaching copper from low grade copper oxide ore was investigated. The effects of leaching temperature, H2SO4 concentration, particle size of crude ore and agitation rate on the leaching efficiency of copper were also evaluated. And the kinetic equations of the leaching process were obtained. The results show that the leaching process can be described with a reaction model of shrinking core. The reaction can be divided into three stages. The first stage is the dissolution of free copper oxide and copper oxide wrapped by hematite-limonite ore. At this stage, the leaching efficiency is very fast （leaching efficiency is larger than 60%）. The second stage is the leaching of diffiuent copper oxides, whose apparent activation energy is 43.26 kJ/mol. During this process, the chemical reaction is the control step, and the reaction order of H2SO4 is 0.433 84. The third stage is the leaching of copper oxide wrapped by hematite-limonite and silicate ore with apparent activation energy of 16.08 kJ/mol, which belongs to the mixed control.

Techniques of copper recovery from Mexican copper oxide ore

Mexican copper ore is a mixed ore containing mainly copper oxide and some copper sulfide that responds well to flotation. The joint techniques of flotation and leaching were studied. The results indicate that an ore containing 19.01% copper could be obtained at a recovery ratio of 35.02% by using sodium sulfide and butyl xanthate flotation. Over 83.33% of the copper oxide can be recovered from the railings by leaching in suitable conditions, such as 1 h stirring at a temperature around 25 ℃with a mixing speed of S00 r/min, an H2SO4 concentration of 1.0 mol/L and a mass ratio of the ore-slurry-liquid to solid （mL/ms） of 3. The overall yield of refined ore after flotation and leaching is over 89.18% of the copper, which is much better than sole flotation or leaching. A copper product containing more than 99.9% copper was obtained by using the process： flotation-agitation leaching- solvent extraction-electro-winning.

Flotation of copper oxide minerals:A review

Copper oxide minerals are important copper resources,which include malachite,azurite,chrysocolla,cuprite,etc.Flotation is the most widely used method for the enrichment of copper oxide minerals in the mineral processing industry.In this paper,the surface properties of copper oxide minerals and their effects on the mineral flotation behavior are systematically summarized.The flotation methods of copper oxide minerals and the interaction mechanism with reagents are reviewed in detail.Flotation methods include direct flotation(using chelating reagents or a fatty acid as collector),sulfidization flotation(using xanthate as collector),and activation flotation(using chelating reagents,ammonium/amine salts,metal ions,and oxidant for activation).An effective way to realize efficient flotation of copper oxide minerals is to increase active sites on the surface of copper oxide minerals to enhance the interaction of collector with the mineral surface.Besides,various perspectives for further investigation on the efficient recovery of copper oxide minerals are proposed.

Copper Oxide Ore Leaching Ability and Cementation Behavior, Mesgaran Deposit in IRAN

One of the Iranian copper deposits that is located east of Iran and also known as a primeval one in that area is Mesgaran Field. Old mining works have been clearly seen in the area. Iran is located on global copper belt and as a result it has numerous potential areas as copper deposits. The purpose of this study is identifying possible potentialities of copper mining in less developed regions of Iran with basic modern technologies. In this study, laboratory investigations of this field were done on samples via leaching and the cementation method. According to the study purposes, acid concentration, temperature, time and pulp density were selected as the main factors that were tested in leaching studies. Moreover, pH, temperature, time and the amount of iron powder were factors which were tested for copper cementation. Optimum conditions of leaching studies with 99.11% recovery rate were obtained after 120 grams per liter of H2SO4, 80 degrees Celsius, 2 hours and 100 grams per liter of solid to liquid. On the other hand, optimum conditions of cementation by iron powder were resulted at more than 95% with a pH of 3, 45 degrees Celsius, 1 hour and 1.5 times more than the stoichiometric equation of required iron powder amount to precipitate copper.

Synthesis of a copper(Ⅱ) oxide–montmorillonite composite for lead removal

The synthesis of a copper(II) oxide–montmorillonite composite and its application in the removal of lead(II) ions in solution were investigated. The Acros Organics (ACOR) montmorillonite was activated using potassium hydroxide solution. The activated ACOR montmorillonite was titrated with copper(II) nitrate solution to produce the copper(II) oxide–montmorillonite composite. Adsorption experiments were conducted using batch-mode techniques under reducing conditions at ambient temperature. The reaction mechanism indicated a higher proton coefficient, greater intraparticle diffusion, and higher mass transfer rates compared with those achieved with bare montmorillonite. The intraparticle diffusion constant derived from the slope was 2.93^-3 (mg·g^–1·min^–0.5), and the intercept C was 9.86,≠ 0. In the presence of a CuO coating, the adsorption efficiency was 85.55% at pH 4 and 89.62% at pH 7. Therefore, the copper(II) oxide-montmorillonite composite, as a novel adsorbent with a very high adsorption capacity, exhibited substantially enhanced adsorption of Pb^2+ ions compared with bare montmorillonite.