Sharif Digital Repository

The new Co(II) - carboxamide complex (1) and Co3O4 nanoparticles (2), by way of thermal decomposition of (1) have been efficiently synthesised in the environment-friendly. X-ray diffraction reveals a slightly distorted octahedral coordination of cobalt (four nitrogens and two oxygens) in (1) and regular octahedral or tetrahedral ones (oxygens only) in (2). The investigation of (1) and (2) in the Mizoroki-Heck and epoxidation of alkens reactions showed them both to be powerful, green and inexpensive catalysts. © 2020 John Wiley & Sons, Ltd  

In the past few years, most studies have focused on smart substances that can respond to changes in the environment, as they can be appropriately applied in different fields, including biosensing, biotechnology, and drug delivery. Here, new fluorescent carbon dots (CDs) are synthesized by Terebinth by designing a simple and single-stage hydrothermal path, which facilitates the manufacture of CDs with no need for boring artificial methods, or using poisonous/costly solvents and starting substances. The method is used to concurrently form CDs and passivate their surface, which results in inherently emitted fluorescence. The study of the structure and optical features of the resulting CDs... 

In this work, flexible thermoelectric fabrics, polyester/yarn fabrics coated with polyaniline/carbon nanotube (PANI/CNT) nanocomposite, were fabricated by sequential processing: (I) polyaniline/carbon nanotube nanocomposites preparation by a one-step in-situ polymerization and (II) dip coating of a mixture solution of CNT-doped PANI on a polyester/yarn fabric. Nanocomposites were synthesized with various CNT content (0.5, 2.5, 5, and 10 wt%) and characterized using different methods. The Seebeck coefficient and electrical conductivity measurements were used to determine their thermoelectric properties. The results revealed significant improvement in both electrical conductivity and the... 

In this research, carbon nanotube decorated with Cu nanoparticles (CNT/Cu) was synthesized by a new solvothermal process. Solvothermal treatment of CuSO4 and NaOH was completed in ethanol containing ultrasonically dispersed CNTs at 160 °C for 3 h. In the solvothermal process, Cu nanoparticles were heterogeneously deposited on the surface of COOH-functionalized CNTs through the reduction of the Cu+2 ions. Cu nanoparticles with the size of ≈8 nm on CNTs (and some in the solution) and strong bonding between Cu and CNT were obtained by the used process. Microstructural characterization revealed that the solvothermal method is an appropriate method for producing homogenous CNT/Cu nanostructure.... 

Herein, two distinct nanocomposites of CaTiO3 micro-cubes and polygonal SrFe12O19, both decorated with NiO nanoparticles, were successfully synthesized using hydrothermal method. The physico-chemical features of as-prepared samples were evaluated via XRD, FTIR, UV–vis, BET, XPS, FESEM and EDS analysis. Microwave attenuation features of as-prepared single layer absorbers were determined by VNA analysis in 2–18 GHz. Simulation confirmation was checked by preparing a bi-layer samples and evaluating it using VNA analysis after finding the appropriate thickness of each layer. The reflection loss from each single layer samples containing 20 wt% of each CaTiO3/NiO and SrFe12O19/NiO nanocomposites... 

The solubility of Pd(NO3)2 in water is moderate whereas it is completely soluble in diluted HNO3 solution. Pd/MIL-101(Cr) and Pd/MIL-101-NH2(Cr) were synthesized by aqueous solution of Pd(NO3)2 and Pd(NO3)2 solution in dilute HNO3 and used for CO oxidation reaction. The catalysts synthesized with Pd(NO3)2 solution in dilute HNO3 showed lower activity. The aqueous solution of Pd(NO3)2 was used for synthesis of mono-metal Ni, Pd and bimetallic PdNi nanoparticles with various molar ratios supported on MOF. Pd70Ni30/MIL-101(Cr) catalyst showed higher activity than monometallic counterparts and Pd + Ni physical mixture due to the strong synergistic effect of PdNi nanoparticles, high distribution... 

The growth of harmful microorganisms is a severe threat to human life. Nowadays, it is necessary to prepare antimicrobials materials with high biocompatibility properties. Hence, the use of nanomaterials and their nanocomposites has been proposed as a suitable way to obtain safe and potent antibacterial materials. Recently, several studies have been conducted on the antibacterial properties of metal oxide and graphene oxide (GO) nanomaterials individually. This study investigated the synergistic effect of GO and copper oxide (CuO) as a nanocomposite. CuO-GO nanocomposite containing 5%, 15%, 25%, 50%, and 75% of GO were synthesized to study antibacterial properties. X-ray diffraction (XRD)... 

The solubility of Pd(NO3)2 in water is moderate whereas it is completely soluble in diluted HNO3 solution. Pd/MIL-101(Cr) and Pd/MIL-101-NH2(Cr) were synthesized by aqueous solution of Pd(NO3)2 and Pd(NO3)2 solution in dilute HNO3 and used for CO oxidation reaction. The catalysts synthesized with Pd(NO3)2 solution in dilute HNO3 showed lower activity. The aqueous solution of Pd(NO3)2 was used for synthesis of mono-metal Ni, Pd and bimetallic PdNi nanoparticles with various molar ratios supported on MOF. Pd70Ni30/MIL-101(Cr) catalyst showed higher activity than monometallic counterparts and Pd + Ni physical mixture due to the strong synergistic effect of PdNi nanoparticles, high distribution... 

The influence of indium on the properties of Cu0.5Zn0.5Fe2O4 nano ferrites synthesized by sol–gel auto-combustion technique was studied. X-ray diffraction (XRD) analysis demonstrated that pure and substituted ferrites possessed cubic spinel structure. The lattice parameter increases with the inclusion of In3+ for x ≤ 0.16 and decreases subsequently. A linear decrease in crystallite size was found as concentration of indium increased. X-ray density, strain, and dislocation density were increased as indium content increases. Hopping lengths as well as radii of A and B sites revealed increasing behavior up to x = 0.16 and decreased thereafter. The spectral bands indicated the formation of... 

Scandium is a rare earth element that is not very abundant on Earth, however in recent years due to the employment of scandium in various high-tech fields the interest in the analytical chemistry of this metal is growing. Currently, the methods for scandium quantification are mainly based on inductively coupled plasma atomic emission and mass-spectrometry and to the best of our knowledge no potentiometric sensors for scandium detection were reported so far. This study is devoted to the development of simple and cost-effective ion-selective sensors for quantification of Sc3+ in aqueous media. Employing the variety of lipophilic ligands suggested in liquid extraction for separation of... 

Rare earth oxides with a trivalent nature play a pivotal role in reinforcing the magneto-optical attributes of spinel ferrite nanoparticles by replacing Fe3+ ions. In this study, rare earth Gd oxide doped with CoFe2O4 NPs with a composition of Co1+xGdxFe2-2xO4 (x = 0, 0.05, 0.10, and 0.15) were synthesized using sol-gel auto-combustion. The outcome of Gd cations on the physical, magneto-optical and electrical characteristics of the cobalt ferrite NPs were reported. X-ray diffraction (XRD), and Fourier transform infrared (FTIR) investigations confirmed the single-phase cubic crystalline nature and metal ion stretching in the cobalt ferrite synthesized samples. Decreasing drift in the average... 

In this study, four types of tetrabutylphosphonium carboxylate ionic liquids (ILs) were synthesized and used for a one-pot transesterification of wet Chlorella vulgaris (C. vulgaris) microalgae into fatty acid methyl esters (FAME) in the presence of methanol, as well as refined oils (sunflower, canola, and corn oil). The resulting process removed the need for complete drying and lipid extraction steps typically needed for biodiesel production from microalgae. The leading candidate ionic liquid catalyst, tetrabutylphosphonium formate ([P4444][For]), was further optimized using response surface methodology to minimize material consumption, increase water compatibility, reduce processing time... 

One of the key parts of perovskite solar cells which has great influence on their performance and stability is hole transporting layer. Spiro-OMeTAD is extensively used as organic hole transporting material in perovskite solar cells. However, Spiro-OMeTAD is expensive and has low chemical stability. In this study, the solution processed Sb2S3 and Cu3SbS4 nanocrystals have been synthesized and then the n-i-p mesoscopic perovskite solar cells have been fabricated using Spiro-OMeTAD, Sb2S3 and Cu3SbS4 nanocrystals as hole transporting layer at ambient air condition. It is shown that the conduction and valence band levels of the synthesized Sb2S3 and Cu3SbS4 nanocrystals are in the proper... 

Water flooding is one of the most common enhanced oil recovery (EOR) methods, however its application in naturally fractured reservoirs (NFR), suffers from the flow of water in high permeable channels and fractures which leads to low areal and volumetric sweep efficiency. Preformed Particle Gels (PPG), as a subset of gel treatments, can play a vital role in plugging super-permeable zones either near wellbore or deep in the reservoir. Nevertheless the mechanical strength and thermal stability of the designed PPGs, especially under harsh environmental conditions, are subject to further research and development. In spite of recent studies, the effects of nano-materials on the rheological and... 

A novel method of oxide semiconductor nanoparticle synthesis is proposed based on high-voltage, high-current electrical switching discharge (HVHC-ESD). Through a subsecond discharge in the HVHC-ESD method, we successfully synthesized zinc oxide (ZnO) nanorods. Crystallography and optical and electrical analyses approve the high crystal-quality and outstanding optoelectronic characteristics of our synthesized ZnO. The HVHC-ESD method enables the synthesis of ZnO nanorods with ultraviolet (UV) and visible emissions. To demonstrate the effectiveness of our prepared materials, we also fabricated two UV photodetectors based on the ZnO nanorods synthesized using the subsecond HVHC-ESD method. The... 

Metal-organic frameworks (MOFs) are a new class of porous crystalline materials being used as photocatalysts for efficient pollutant removal and environmental remediation. In this study, the TMU-32 MOF was synthesized as an effective photocatalyst for the photodegradation of tetracycline (TC) with 96% efficiency in 60 min under visible light. The high photocatalytic activity of the TMU-32 MOF is mainly due to its large specific surface area, which is beneficial for promoting both the adsorption of TC and the separation of the photoinduced charges. Moreover, its desired crystallinity makes it a semiconductor with an appropriate band gap energy. Next, a composite of the TMU-32 MOF with Fe3O4... 

Metal-organic frameworks (MOFs) are a new class of porous crystalline materials being used as photocatalysts for efficient pollutant removal and environmental remediation. In this study, the TMU-32 MOF was synthesized as an effective photocatalyst for the photodegradation of tetracycline (TC) with 96% efficiency in 60 min under visible light. The high photocatalytic activity of the TMU-32 MOF is mainly due to its large specific surface area, which is beneficial for promoting both the adsorption of TC and the separation of the photoinduced charges. Moreover, its desired crystallinity makes it a semiconductor with an appropriate band gap energy. Next, a composite of the TMU-32 MOF with Fe3O4... 

The growth of harmful microorganisms is a severe threat to human life. Nowadays, it is necessary to prepare antimicrobials materials with high biocompatibility properties. Hence, the use of nanomaterials and their nanocomposites has been proposed as a suitable way to obtain safe and potent antibacterial materials. Recently, several studies have been conducted on the antibacterial properties of metal oxide and graphene oxide (GO) nanomaterials individually. This study investigated the synergistic effect of GO and copper oxide (CuO) as a nanocomposite. CuO-GO nanocomposite containing 5%, 15%, 25%, 50%, and 75% of GO were synthesized to study antibacterial properties. X-ray diffraction (XRD)... 

CO2 separation is of paramount importance owing to global warming abatement, as well as sour natural gas sweetening. Mixed matrix membranes (MMMs), containing porous zeolitic imidazolate frameworks (ZIFs), in particular ZIF-8, have drawn noticeable attention due to their favorable separation performance. However, there are evidences of discrepancies in the reported values of gas diffusion coefficients/diffusivities through ZIFs, even for common well-studied gases, such as CO2 and CH4 in the literature. These discrepancies might be attributed to the surface/barrier effects, which are intensified by ZIF-8 nanocrystals downsizing. In this paper, an effort has been made to determine the impact... 

Polyvinylpyrrolidone coated nano zero valent iron-copper (PVP-nZVI-Cu) bimetallic nanoparticles were successfully synthesized for dechlorination of trichloroethylene (TCE) into non-toxic byproducts in the presence of persulfate oxidant. The average size of PVP-nZVI-Cu nanoparticles (3-25 nm) was smaller than PVP-nZVI (25-60 nm) and nZVI (50-90 nm) particles due to PVP role in the prevention of iron aggregation and agglomerations. The synthesized PVP-nZVI-Cu nanoparticles were used as an efficient persulfate (PS) activator to generate reactive oxygen species (ROSs) for the degradation of TCE. The complete removal of TCE (99.6%) was achieved in the presence of 0.4 g/L of PVP-nZVI-Cu...