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Background Selective catalytic oxidation of alcohols to the corresponding aldehydes and ketones is one of the most important functional transformations for producing fine chemicals owing to the versatile role of the carbonylic group as a building block. Methods In this work, four types of mixed metal oxides were designed and synthesized. Three types of these mixed metal oxides (Pd.PdO.CuO, La2O3-CuO and ZnO-CuO) had hollow sphere structure, whereas MnO2-CuO had uniform nanoparticles shape. Pd.PdO.CuO contained two parts, one was the CuO hollow spheres and the other are the Pd.PdO scattered nanoparticles which were decorated on the interior and exterior surfaces of CuO hollow spheres. The as-prepared composites were characterized by FESEM, HRTEM, EDS, XRD, and ICP techniques. These new mixed metal oxides were successfully applied to catalysis of the oxidation reaction of alcohol to aldehyde. Significant Findings The results showed that these nanoparticles on the CuO hollow spheres have a synergistic effect which enhances the efficiencies of the catalysts in the oxidation reaction. This method was highlighted by its broad substrate scope, environmentally friendly reaction conditions (the reaction proceeded in water), the recyclability of the catalyst, low catalyst usage, operational simplicity and high yields.

Metal-oxide nano-porous microstructures have shown high electrocatalytic activity toward hydrogen peroxide oxidation. In this paper, we establish the copper oxide (CuO) porous hollow structures via the hydrothermal method using pluronic F-127 as a surfactant. The electrochemical performance involves the oxidation between Cu(I) and Cu(II) at room temperature. For verifying the formation of the desired morphology of CuO porous hollow structures, the scanning electron microscopy, Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction spectroscopy and H2-temperature-programmed reduction (TPR) were applied. The synthesized samples are hollow microstructures which are formed by CuO nanoparticles. The achieved CuO hollow structures exhibit excellent H2O2 detection properties such as a very low detection limit of 141.1 nM, an extremely wide dynamic detection range of 50 nM–70 mM, an outstanding sensitivity of 13.7 µA µM−1 cm−2 and satisfactory stability in alkaline solution. The good tolerance toward interfering species, the satisfactory behaviour in repeatability and reproducibility and favourable stability verified the promising performance of the proposed sensor. The results of the study on sensing low levels of H2O2 concentrations by using a modified glassy carbon electrode as an optimized electrochemical sensor have been reported. The proposed synthesized nanostructures (CuO porous hollow structures) can be used as sensitive H2O2 biosensors. Essential characterizations and measurements have been performed. The constructed sensor shows acceptable electrocatalytic activity for detecting H2O2. High sensitivity, very low LOD, wide dynamic range, excellent tolerance toward interfering agents, favorable stability and satisfactory reproducibility and repeatability of the sensor have made it suitable for practical applications.

A high-performance non-enzymatic glucose sensor based on hybrid metal-oxides is proposed. Dumbbell-shaped double-shelled hollow nanoporous CuO/ZnO microstructures (CuO/ZnO-DSDSHNM) were prepared via the hydrothermal method using pluronic F-127 as a surfactant. This structure is studied by various physicochemical characterizations such as scanning electron microscopy, X-ray diffraction spectroscopy, inductively coupled plasma atomic emission spectroscopy, elemental mapping techniques, X-ray photoelectron spectroscopy, and transmission electron microscopy. This unique CuO/ZnO-DSDSHNM provides both a large surface area and an easy penetrable structure facilitating improved electrochemical reactivity toward glucose oxidation. The prepared CuO/ZnO-DSDSHNM was used over the glassy carbon electrode (GCE) as the active material for glucose detection and then coated by Nafion to provide the proposed Nafion/CuO/ZnO-DSDSHNM/GCE. The fabricated glucose sensor exhibits an extremely wide dynamic range from 500 nM to 100 mM, a sensitivity of 1536.80 µA mM−1 cm−2, a low limit of detection of 357.5 nM, and a short response time of 1.60 s. The proposed sensor also showed long-term stability, good reproducibility, favorable repeatability, excellent selectivity, and satisfactory applicability for glucose detection in human serum samples. The achieved high-performance glucose sensing based on Nafion/CuO/ZnO-DSDSHNM/GCE shows that both the material synthesis and the sensor fabrication methods have been promising and they can be used in future researches.

A reusable, eco-friendly, long-lived and efficient nanocatalyst, imidazolium-based ionic liquid immobilized on functionalized magnetic hydrotalcite (Fe3O4/HT-IM, IM is known as imidazolium-based melamine), was successfully introduced. The structure of the synthesized nanocatalyst was characterized by several techniques which revealed a plate-like shape with an average particle size of approximately 50 nm and also the presence of acidic sites (site density: 12 mmol g−1). The catalytic activity of Fe3O4/HT-IM was explored in the chemical fixation reaction of carbon dioxide towards the preparation of cyclic carbonates under optimized reaction conditions at 100 °C, 0.7 MPa and 1.6 mol% of the nanocatalyst. This reaction was conducted without using any metal, additive, toxic reagents and solvent/co-catalyst which provides mild and green conditions from the standpoint of green chemistry. Owing to having acidic-basic sites which can simultaneously accelerate the ring-opening of the epoxy ring and incorporation of CO2, this catalyst is attractive and suitable for this reaction. In particular, the prepared catalyst can be easily separated using an external magnetic field and reused over six times without any significant loss in catalytic performance and selectivity. This proves its great potential to be implemented for industrial purposes as a green catalyst.

The first report of the use of an acidic magnetic metal organic framework for the chemical fixation of CO2 as an environmentally friendly reaction.

A new, efficient and convenient method for the synthesis of 5-substituted 1H-tetrazole derivatives with a wide range of substituents in good to excellent yields has been developed. The synthesis was performed by the one-pot three-component [3+2]cycloaddition reaction between aldehyde, hydroxylamine and sodium azide in the presence of Cu/C. The reaction probably proceeds by the in situ formation of nitriles followed by successive [3+2]cycloaddition with sodium azide. A variety of aldehydes were used to obtain the corresponding tetrazoles. The catalyst was recovered by simple filtration and reused at least five times without significant loss of catalytic activity. The use of this method offers additional advantages for the synthesis of 5-substituted 1H-tetrazole derivatives, including the easy availability of starting materials, mild conditions, experimental simplicity and good yields.

A novel hollow CoAl2O4 microsphere was synthesized by hydrothermal method and used to selectively convert CO2 and CS2 to cyclic carbonates and trithiocarbonates under the solventless condition. Various techniques such as powder X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), as well as N2 and CO2 adsorption measurements have been used for characterization of catalyst. The effects of reaction parameters such as temperature, time and pressure were investigated. The catalyst showed a good performance for conversion of a wide range of epoxides, giving almost satisfactory yields and high selectivity for carbonates and trithiocarbonates. In addition, the catalyst showed high stability and could be reused after regeneration at least for six times. This process also could be regarded as an efficient way for CO2 conversion for production of valuable organic compounds.

Designing complex hollow nano-/microspheres with multilayered structures of two or more metal oxides seems to be interesting to answer the request for novel catalytic structures. Herein, we develop a copper-alumina spinel hollow sphere with a triple-shell structure applied as a novel catalyst for the cycloaddition of CO2 at atmospheric pressure. Different operating conditions such as reaction temperature, various solvents and reaction time were studied in this reaction. Besides, different epoxides were converted at 80 °C, under bubbling of CO2 at atmospheric pressure, a catalyst loading of 3 wt.% and a reaction time of 24 h with isolated yields up to 100% of the carbonate. In addition, the kinetics of the reaction was investigated at different reaction temperatures by calculating the reaction rate constant and activation energy (based on the Arrhenius equation). The nanoporous triple-shell CuAl2O4 hollow microspheres reduce the mass transfer path of different reactant and product molecules along with better accessibility of interior active sites that improves the catalytic efficiency with suitable activity and remarkable cycling stability.

A new nanoreactor type structure composed of hollow mesoporous silica spheres and CuO nanoparticles loaded inside the interior cavity of spheres has been designed and successfully prepared. The synthesis method is proceed in a four step procedure by using carbon spheres as the hard template together with a coating of tetraethyl orthosilicate (TEOS) and cetyltrimethyl ammonium bromide (CTAB) mixture. The obtained nanoreactors were characterized with FE-SEM, elemental mapping, TEM, XRD, BET, ICP and TPR analysis. The CO2 fixation reaction is applied to evaluate the catalytic performance of the synthesized CuO@SiO2 multi-yolk@shell catalyst. This catalyst exhibits superior activity in CO2 fixation reactions with 96% yield in 4 h at low pressure. The catalyst demonstrates superb mechanical stability, high activity and is recovered for at least six times without loss of activity in CO2 fixation reaction, showing that this type of nanoreactor could be applied as a promising material in advanced catalysis applications.

In the present study, an electrochemical glucose biosensor has been developed based on nano-copper oxide micro hollow spheres. The nano-copper oxide micro hollow spheres were synthesized via hydrothermal method using pluronic F-127 as a surfactant. For structural characterization of CuO hollow sphere structures, the scanning electron microscopy and X-ray diffraction spectroscopy were applied. The performance parameters of the sensor were improved by optimizing the modification process. The electrochemical characteristics of the proposed glucose biosensor were investigated by using cyclic voltammetry and chronoamperometry techniques in both 0.1 M and 1 M NaOH solutions. The results revealed that the proposed electrode has a wide dynamic range from 1 µM to 11.50 mM for glucose detection at 0.1 M NaOH solution which covers two linear ranges from 1 µM to 3 mM and from 3 mM to 11.50 mM. The sensitivities of the two linear ranges were obtained as 25.0 ± 0.8 µA·mM−1·cm−2 and 13.6 ±0.3 µA·mM−1·cm−2, respectively. An extremely wide linear range from 1 µM to 16 mM with a sensitivity of 35.2 ± 0.4 µA·mM−1 cm−2 was achieved for the 1 M NaOH solution. The sensor achieved a 1 µM practical lowest limit of detection which is an excellent low limit of detection at both NaOH concentrations compared to some important previously reported works. In addition, the good tolerance toward the interfering species and the satisfactory behavior in real sample analysis verified the promising performance of the proposed sensor.

In this study, biodiesel was produced from goat fat in the presence of calcium oxide nanocatalyst. For this purpose, the surface characteristics of the nanocatalyst were investigated using differen...

The imidazole ring system is one of the most important heterocyclic substructures and has been found in a large number of pharmacologically active compounds, including the fungicide ketoconazole,1 ...

To study the effect of four interventions on lower back pain (LBP) alongside time and to identify whether changes in nutrition and doing traditional Persian remedies (massage and rubbing white Lily oil) could relieve the LBP using a short-time treatment. The population of this study consisted of 89 subjects with chronic LBP collected in traditional Persian medicine clinics. The outcomes were two indices for LBP, Oswestry disability index (ODI), and numerical rating scale (NRS), measured three times with an interval of four weeks. Age was not an effective variable in both LBP indices. Effective interventions for both indices are almost the same. For ODI, sex (= male), nutrition, massage, using White Lily oil, and time had decreasing effects on ODI, but interactions of sex with nutrition and massage had increasing effects on ODI. For NRS, sex (= female), using White Lily oil, time, and interactions of sex with massage and nutrition had decreasing effects, but nutrition, massage, and interactions of sex with White Lily oil had increasing effects on NRS.

Air pollution has been identified as one of the most challenging health issues in urban areas worldwide. The aim of this study was to investigate the association between short-term exposure to ambient air pollution and respiratory disease over a long-term period in Shiraz, one of the largest cities in Iran. Methods: hospital admissions due to respiratory diseases (asthma, pneumonia, chronic obstructive pulmonary disease (COPD) and pleural effusion) in residents of Shiraz between March 21, 2009 and March 20, 2015 were included. Demographics for each patient and meta data to include principal meteorological variables (temperature and relative humidity) and five ambient pollutants (CO, O3, SO2, NO2, and PM10) were also included. Statistical analysis was performed by Poisson regression in single-pollutant generalized linear model with principal component analysis (GLPCA) to analyze the relationship between pollutants and hospital admissions at the 0–9 cumulative lag day period. Pearson correlation test was used to determine the relationship between different pollutants, temperature and humidity. Results It was found that the highest increase in asthma admission was related to PM10 (relative risk (RR) = 1.31, 95% CI = 1.17, 1.47). For COPD, the rate of hospital visits significantly increased with the increase in NO2 concentration (RR = 1.17, 95% CI = 1.09.1.27). In the children's hospital, O3 (RR = 1.25, 95% CI = 1.06, 1.47) and SO2 (RR = 1.17, 95% CI = 1.07, 1.28) affected the asthma admissions and all contaminants (highest RR observed was for NO2 (RR = 1.28 95% CI = 1.18, 1.40) affected pneumonia admissions on cumulative lag days of 0–9. Conclusions: These data confirm an association between ambient air pollutants and hospital admissions due to respiratory disease.

Cage like CuFe2O4 hollow nanostructure has been synthesized successfully using hard template method under the hydrothermal condition. Cu(NO3)2·6H2O, Fe(NO3)2·9H2O and glucose were dissolved in water, and the mixture was heated to 180 °C in an autoclave. The removal of carbon was achieved by calcination at 800 °C and finally, the cage like CuFe2O4 hollow structure was obtained. This cage like CuFe2O4 hollow structure was characterized by FE-SEM, EDS, TEM and XRD. The catalytic performance of this hollow nanostructure was evaluated for the synthesis of bis pyrazol-5-ols. To this end, the one pot condensation reactions of phenylhydrazine, ethyl acetoacetate and different aromatic aldehyde at 80 °C under the solvent free condition were performed. The optimum amount of applied catalyst for this transformation was obtained to be 0.04 mol %. Noteworthy, catalyst was easily recoverable and was reused for 7 times with the remaining of its initial structure as well as its catalytic activity. Cage like CuFe2O4 hollow nanostructure are stably and efficiently attainable for conversion of precursors to 4,4′-(aryl methylene)bis(3-methyl-1H-pyrazol-5-ol)s

In this work, thermophysical properties for five binary mixtures of 2-hydroxy ethyl ammonium formate (2HEAF) + 1-propanol, +2-propanol, +1, 2-propanediol, +2-methyl-1-propanol, and +2-methyl-2-propanol have been measured over the 298.15 to 323.15 K temperature range at atmospheric pressure. The experimental data were used to calculate derived excess and mixing properties, which were discussed in terms of the nature and strength of intermolecular interactions in these mixtures and its evolution with mixture composition and their relationship with the inferred large non-ideality of these mixed solvents. Likewise, molecular dynamics simulations in the full composition range allowed a microscopic level characterization of mixed fluids' structuring, hydrogen bonding as a function of mixtures components and composition and its relationship with macroscopic thermophysical properties.

An efficient and straightforward protocol for direct synthesis of 2H-indazoles is achieved from consecutive condensation of 2-halobenzaldehydes, primary amines, and sodium azide catalyzed by heterogeneous copper nanoparticles on charcoal (Cu/C) is achieved. The recoverable heterogeneous copper nanoparticles on charcoal (Cu/C) catalyst exhibited an impressive activity for the title reaction without any additives (expensive ligands, etc.). A series of structurally diverse 2H-indazoles were prepared in good to excellent yields from easily accessible starting materials by employing this protocol.

A New and efficient magnetic nanocatalyst has been fabricated via covalent grafting of an aza-crown ether Cu(II) complex on silica coated iron oxide support. The above mentioned magnetic nanocatalyst has been characterized by various techniques such as SEM, TEM, XRD, FT-IR, TGA and ICP. After preparation, the applicability of this catalyst in the synthesis of triazole and tetrazole derivatives was studied. The prominent features of the present methodology are: high yields, short reaction times, easy preparation, magnetical separation and favorable recoverability of the catalyst (for at least five runs without significant loss of catalytic activity).

Here, a novel nanostructured catalyst based on CuO included hallow mesoporous silica spheres (CuO–HMSS) was prepared for synthesis of 1,2,3-triazole compounds. The hallow silica spheres were synthesized via the hydrothermal procedure. The characterization of prepared catalyst was also performed applying several analysis techniques such as TEM and SEM, EDX, XRD, and ICP. CuO active sites in a hollow mesoporous silica shell are stably and efficiently attainable for conversion of precursors to triazole compounds.

Air pollution and dust storms are associated with increased cardiovascular hospital admissions. The aim of this study was to investigate the association between short-term exposure to ambient air pollutants and CVD (cardiovascular disease) events in a long-term observational period. The study included the events of cardiovascular diseases (namely coronary artery disease, ischemic heart disease, myocardial infarction, and pneumo thrombo embolism) within the population of Shiraz, from March 21, 2009 to March 20, 2015. Also, each patient’s demographics were recorded. Main meteorological variables and five ambient pollutants (CO, O3, SO2, NO2, and PM10) were recorded. Statistical analysis was performed using linear regression (GLM) and a generalized additive model (GAM) estimating Poisson distribution and adjusted for the main risk factors and ambient meteorological variables. A mild prevalence (51.5%) of coronary artery disease (CAD) was registered in 6425 events. In GLM analysis, we observed an association among the pollutants with the coronary artery disease hospital admissions which was in the order of CO, NO2, and PM10. The highest association of each pollutant with hospital admission was observed as PM10 at lag 4 (RR = 1.08; 95% CI 1.02, 1.14 and p

The sequestration of atmospheric CO2 into value-added products is of great interest from economic and environmental perspectives. The tetra-shelled Cr1.3Fe0.7O3 hollow sphere as a heterogeneous catalyst was synthesized by a simple hydrothermal method followed by calcination at 600 °C. The synthesized tetra-shelled hollow spheres were characterized by several effective tools. The catalytic performance was studied for the cycloaddition reaction of CO2 with epoxides under solvent-free conditions. The reaction time, reaction temperature, CO2 pressure, and the catalyst amount were systematically studied. Under the best-experimented condition ( 0.02 g of the catalyst, 80 °C, 6 h, and 4 bar CO2 pressure), the catalyst demonstrated a broad substrate scope and functional group tolerance. Besides, the catalyst showed high recycling efficiency for five consecutive reaction cycles with no significant decline in activity.

Design of complex hollow microspheres with double-layered constructions of spinel metal oxides appears to be remarkable in order to supply the need for innovative catalysts. In this study, a CuCo2O4 hollow sphere catalyst was developed for the cycloaddition of carbon dioxide to epoxides. Different operating conditions such as reaction temperature, reaction pressure, reaction time, catalyst weight percentage, and various co-catalysts and epoxides are studied in this reaction. Consequently, the optimized operating conditions are achieved including 80 °C, 5 bar, the catalyst weight percentage of 3.2 and 3 h reaction time with the production yield of about 96% for the produced carbonate. The reaction rate was studied to analyze the performance of synthesized catalysts using the activation energies and reaction rate constants along with thermodynamic parameters. The attained double-shell hollow sphere Cu–Co spinel structure revealed remarkable activity and superior production performance as the catalyst for the fixation of carbon dioxide with epoxide.

This work aims to report not only the new measurement for densities of 2-hydroxy ethylammonium formate (2-HEAF) ionic liquid under high-pressures but also molecular dynamics considerations of nanoscopic characterization for physicochemical properties in the pressure range studied. High-pressure densities of 2-HEAF showed smooth trends with temperature and pressure variations. Measurements were carried out at temperatures T = (298.15 to 333.15) K and at pressures P = (0.1 to 40) MPa. The high-pressure densities of 2-HEAF have also been correlated by the use of Tait equation with AARD equal to 0.031% and the mechanical coefficients including the isothermal compressibility, isobaric expansivity and thermal pressure were estimated. Molecular dynamics simulations were carried out in the same pressure – temperature range as the experimental study. Force field was validated against experimental results and the microscopic structure was analyzed in terms of intermolecular interactions and their evolution with temperature and pressure., Iran National Science Foundation for supporting this project via the grant number (INSF-96000966)

Triple-shell hollow spheres of crystalline copper–nickel ferrite have been synthesized in a simple one-pot procedure using carbon spheres as templates via a hydrothermal approach. Ferric nitrate , copper nitrate, and nickel nitrate were dissolved in water together with glucose, and the mixture was heated to 180 °C in an autoclave. Finally, the carbon core was removed by calcination at 550 °C. The triple-shell hollow spheres of CuNiFe 2O4 were characterized by XRD, TEM, FE-SEM, and EDS. High catalytic activity for the Suzuki reaction was obtained for this new triple-shell hollow sphere of CuNiFe2O4. This also reveals obvious advantages such as the recyclability of the catalyst, simple experimental operation, and excellent yields.

In this paper, we introduced pyridinyl benzimidazol (PBI) as an easy-to-handle and bidentate N-chelating ligand that promote clean synthesis of 3,5-disubstituted isoxazoles in the presence of copper acetate as catalyst. This catalytic approach initiates with the hydroxyamination of aldehydes followed by chlorination and then generation of nitrile oxide which subsequently undergoes click-type [3 + 2]-dipolar cycloaddition with alkynes to give isoxazoles. This method provides an alternative green process to construct isoxazole derivatives.

This work reports an experimental and theoretical study on 2-hydroxyethylammonium formate (2-HEAF) protic ionic liquid. Relevant physicochemical properties, density, speed of sound, dynamic viscosity and surface tension, were measured as a function of temperature in the 298.15 to 328.15 K range. Likewise, the solubility parameter of 2-HEAF was estimated at different temperatures according to Eyring's approach. Theoretical studies using density functional theory (DFT) and molecular dynamic simulations were carried out for the nanoscopic characterization of the selected ionic liquid and its relationship with macroscopic properties. The interfacial behavior regarding to air interfaces was also studied using molecular dynamics simulations. The possible cytotoxicity of 2-HEAF was theoretically studied using molecular dynamics considering the interaction of this ionic liquid with model lipidic biomembranes formed by 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine. The reported results lead to a full characterization of this representative protic ionic liquid from micro and macroscopic viewpoints including toxicity issues, and thus contributing to the understanding of the properties of ionic liquids and the development of structure-property relationships.

The properties of N-methyl-2-pyrrolidonium hydrogen sulfate mixed with alkanols are studied as a function of mixtures composition and temperature. Experimental physicochemical properties combined with molecular simulation (quantum chemistry and classical molecular dynamics) were considered, thus providing a micro and macroscopic characterization of fluids' structuring, intermolecular forces and molecular aggregation. The results were analyzed in thermodynamics terms considering deviations of ideality and mixing properties as well as from the coordination and interaction between the involved ions and molecules by the developed complex hydrogen bonding networks. The results allow a multiscale characterization of the considered mixed systems thus providing the required information for the possible applications of low viscous protic pyrrolidonium-based ionic liquids and their mixtures with relevant hydrogen bonding molecular cosolvents.

In a simple, common and repeatable procedure gold nanoparticles (NPs) were encapsulated into the mesopores of tris-(2-aminoethyl)-amine functionalized SBA-15 and non-functionalized SBA-15 as a host with size controlling and stabilizing ability. After full determination and characterization of morphological, chemical and physical structure of catalysts, the catalytic activity of these gold based catalysts were compared in the coupling of CO2 with epoxides. Various five-membered cyclic carbonates were obtained in high yield under solvent free condition with several epoxides undergo CO2 fixation reaction. Well stabilized gold NPs into the modified meso-channels of SBA-15 were used as an efficient and highly active catalyst. The effect of organic linker on the size, dispersity, metal loading capacity, activity and reusability of the catalyst was also investigated. Different parameters such as catalyst loading, temperature, CO2 pressure and reaction time were optimized.

The facile and effective synthesis procedure of an innovative tricationic ionic liquid was performed with determination of its physical and chemical properties. The absorption properties and application of the as-prepared aqueous phase ionic liquids was examined as a potential future solvent. The influence of absorption temperature and the concentration of ionic liquid was determined at different equilibrium pressures in the range of 90–240 kPa. The tricationic ionic liquid revealed to be advantageous as effective solvent for the absorption of carbon dioxide according to the functional groups and high structural flexibility.

In this work, copper nanoparticles loaded on Fe3O4@SiO2, which we have named Fe3O4@SiO2/EP.EN.EG@Cu for short, have been designed, prepared and characterized by XRD, FTIR, TEM, SEM, EDS, TGA, ICP, successfully. The catalytic performance was investigated in the reduction of aromatic nitro compounds in the presence of NaBH4 aqueous solution as the source of hydrogen at 50 °C. The Fe3O4@SiO2/EP.EN.EG@Cu catalyst was readily removed from the reaction mixture by applying an external magnet and reused for five times without significant loss of catalytic activity.