Nanochemistry Research
Volume:6 Issue: 2, Summer-Autumn 2021

HPA-ZSM-5 nanocomposite as a green heterogeneous catalyst was utilized for the synthesis of furans by the three-component reaction of phenylglyoxal, dimethyl acetylenedicarboxylate and primary amines. The best results were obtained in the presence of 6 mg of HPA-ZSM-5 nanocomposite in CH2Cl2 at room temperature. The zeolite catalyst has been characterized by X-ray diffraction (XRD), field emission scanning electron microscopes (FE-SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared (FT-IR), and N2-adsorption analysis. Experimental simplicity, wide range of products, excellent yields in short reaction times, reusability of the catalyst, and low catalyst loading are some of the substantial features of this method.

Scanning Electron Microscopy (SEM), an easily acquired and widely applied image acquisition and analysis method, have rarely been used to study the pore structure of poly(ethylene terephthalate) knitted fabrics after ultraviolet irradiation simultaneously ozone gas exposure. In this work, we present an investigation of nano-dimension detection of the pores and fractures using SEM observations. The morphological characteristics of the poly(ethylene terephthalate) fabric surface can be revealed by SEM method. By detecting 9 high resolution SEM images, the pores morphology of different scales were acquired. And the studied poly(ethylene terephthalate) knitted substrate shows different types of pores and holes with multi-resolution at the surface layer after ultraviolet irradiation and ozone gas exposure for 80 minutes. This work demonstrated that the combination of two dimensional (2D) SEM results is effective in detection of surface morphology, and is of significance in revealing the pore structure of materials at nano dimension scale. Sub-micron porosity with pore radii as small as 2.5–10 nm was observed in SEM cross-sections. The formation of nano dimensional pores on the surface of the fabric is because of the physical etching ( due to the ion bombardment in the radiation chamber).

Double bloom purple Rose of Sharon, with the scientific name of Hibiscus Syriacus Ardens in the family of Malvaceae, was collected from Mazandaran, Iran in spring, dried in the shade, and powdered. The powdered flower material was extracted in ethanol (70% (V/V)). Samarium oxide nanoparticles (Sm2O3 NPs) were synthesized by using the Rose of Sharon flower extract. The morphology and structure of NPs were determined by FT-IR, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy dispersive spectra (EDS). Then, biosynthesized Sm2O3 NPs was used as a highly efficient catalyst for the synthesis of benzimidazole derivatives. These compounds were synthesized by the reaction of o-phenylenediamine and some sugars in the presence of Sm2O3 NPs (5 mol%) in ethanol 70%. The assigned structure was further established by CHN analyses, NMR, and FT-IR spectra. The catalyst was simply recovered, washed with ethanol, and reused 4 times without significant loss of activity.

In recent years, intensive attempts have been made to remove toxic heavy metals and radionuclides from wastewater. Uranium is one of the most threatening elements due to its radioactivity and high toxicity. Significant amounts of uranium are released into the environment throughout the nuclear fuel cycle. Biosorption technology offers the advantages of low operating costs and high efficiency for metal removal from aqueous solutions. In this work, the sorption of uranyl ions from aqueous solutions by Saccharomyces Cerevisiae (SC) as free cells and in an immobilized form on Zeolite Clinoptilolite was investigated. First, a characterization of the natural zeolite was carried out by classical chemical analysis, XRD, FTIR, and TG/DTG, and then the influence of solution pH, temperature, contact time, and initial concentration on uranyl sorption was investigated. The concentration range of uranyl in the solution was between 0.02 and 1 mmol L-1, which was determined by the ICP-OES method. In addition, the immobilization of 17.1 × 108 cells ml-1 number of yeast cells on clinoptilolite was optimized and observed using an SEM. More results demonstrated that metal binding was carried out extracellularly at the cell wall surface and the rate of uranyl ion uptake by free yeast cells of SC is rapid. The equilibrium adsorption ratio for all samples was calculated and showed that the points corresponding to initial concentrations lower than about 0.1 mmol L-1 have a higher and closer absorption fraction. Moreover, at concentrations higher than 0.2 mmol L-1, the adsorption rate decreases compared to low concentrations.

Acid functionalized multi-walled carbon nanotubes (MWCNTs)-COOH was reacted with La(NO3)3.6H2O in acetic acid by ultrasonication at 60oC to gain (MWCNTs)-COOH/La2O3 hybrid. This nano-material was used as an efficient catalyst for the synthesis of some heterocycles containing nitrogen Acridine and indole derivatives were obtained with the reaction of isatin or dimedone with some amino compounds such as thiosemicarbazone, amino acids, and anthranilic acid by using of (MWCNTs)-COOH/La2O3 (5 mol%) in ethanol under reflux conditions. The products were gained in mild reaction conditions and good yields and identified by CHN analysis, NMR, and FT-IR spectra. the amount of La or La2O3-loading in (MWCNTs)-COOH/La2O3 was measured using The inductively coupled plasma–atomic emission spectroscopy (ICP-AES) analysis. The leaching of catalyst has been measured by using a hot filtration method. there was no leaching to confirm the stability of the catalyst. The catalyst was simply separated at the end of the reaction, washed, dried, and re-entered to a fresh reaction mixture 5 times without considerable loss of activity.

In the present study, the Ag NPs/Zeolite 13X nanocomposite as an effective catalyst was prepared through reduction of Ag+ ions using Tragopogon graminifolius extract as the reducing and stabilizing agent and Ag NPs immobilization on Zeolite 13X surface in the absence of any stabilizer or surfactant. Several techniques such as FT-IR spectroscopy, UV-Vis spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray Spectroscopy (EDS) and Transmission Electron Microscopy (TEM) were used to characterize Zeolite 13X, Ag NPs, and Ag NPs/ Zeolite 13X. Moreover, the catalytic activity of the Ag NPs/Zeolite 13X nanocomposite was investigated in the reduction of 4-nitrophenol (4-NP) and chromium (VI) at room temperature. On the basis of results, Ag NPs/Zeolite 13X nanocomposite was found to be high catalytic activity according to the experimental results in this study. In addition, Ag NPs/Zeolite 13X nanocomposite can be recovered and reused several times in the reduction of 4-NP and chromium (VI) with no significant loss of catalytic activity.

Pure and Yb3+-doped ZnS (YbxZn1−xS) nanoparticles were prepared in this research via hydrothermal route at 160 °C and 12 h. The obtained products were characterized by means of Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and X-ray powder diffraction (XRPD). XRPD analyses displayed that the particles were perfectly crystallized and assigned to the cubic structure of zinc sulfide. TEM and SEM images indicated that the sizes of particles were in the range of 10-80nm.The photocatalytic performance of Yb3+-doped ZnS nanoparticles was assessed in an aqueous solution by observing the decolorization of Tartrazine (Yellow 5) in the process of visible-light radiation. The degradation percent of Yb0.06Zn0.94S and bare ZnS was 92.15 and 22.10% after 100 min of treatment, respectively. 6% Yb3+-doped ZnS nanoparticles demonstrated the highest removal efficiency between various values of dopant agent. It was noticed that the existence of inorganic ions like C2O42−, I−and other radical scavengers like benzoquinone and butanol decreased the decolorization efficiency.

Over the last decade, the usage of metal-organic frameworks (MOFs) for electrochemical applications has grown in popularity. The sensitivity of amperometric sensors, which use currently as the sensing response for the targeted analyte is one of the most often encountered electrochemical sensing systems. Electrocatalysts with high reaction rates and the ability to selectively react with the intended analyte are generally required. Because electrochemical reactions may only occur on the surface of an electrode, depositing or immobilizing the electrocatalyst on the surface of an electrode to produce a modified electrode is a typical technique for constructing the active electrode of an amperometric sensor. As we know, multiple chemical functionalities can be incorporated into the entire pore structure of MOFs with different synthetic routes without losing much porosity. However, because most MOFs are not chemically stable in water, and most electrochemical sensing systems require the use of aqueous electrolytes, water stability of MOFs becomes one of the primary issues for MOF usage in electroanalysis. Only lately have significant attempts been made to manufacture MOFs utilizing biomimetic mineralization methods, in which biomolecules are employed as crystallization and guiding agents to design a variety of MOFs. MOF-based particles containing biomolecules such as enzymes, proteins, peptides, cells, DNA, and viruses have been synthesized using this technique. This review summarizes recent developments of MOF-‎biomolecule composites with special emphasis on preparative techniques and the synergistic effects of biomolecules and MOFs. The applications of MOF-‎biomolecule composites in electrosensing are presented as well.

In this work, a novel electrochemical sensor was introduced for simultaneous determination of dopamine (DA) and epinephrine (EP) by modifying a glassy carbon electrode (GCE) with reduced graphene oxide (RGO) and titanium dioxide (TiO2) nanoparticles. The RGO/TiO2 nanocomposite characterization was investigated by using Field emission scanning electron microscopy (FE-SEM), Elemental mapping, Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-Ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods were used for electrochemical measurements. Our study showed that the resultant RGO/TiO2 modified GCE is highly sensitive and selective for the simultaneous determination of DA and EP, and provided two linear responses ranges from 5-180 µM, 180-1000 µM with a detection limit of 1.3 µM for DA and two linear responses ranges from 5-20 µM and 20-1000 µM with a detection limit of 1.4 µM for EP. Also, the electrochemical oxidation of DA and EP was well recovered in pharmaceutical formulations.

Additive interfacial engineering is a strategy to enhance the performance of perovskite solar cells (PSCs). The high-quality perovskite active layer, with defect-free, plays a key role in the performance of the solar cells. In this paper, dopamine hydrochloride (DA), as an organic ligand was incorporated into the CH3NH3PbI3 perovskite precursor solution, and the effects of DA addition on the microstructure of perovskite films and the photovoltaic properties of the PSCs have been studied. It is found that the addition of DA in perovskite precursor is a promising strategy for obtaining compact and uniform CH3NH3PbI3 film, whic can effectively reduce the recombination of charge carriers. The PSCs grown with DA additive in perovskite precursor, significantly show enhanced photovoltaic performance. An optimum power conversion efficiency (PCE) of 13.57% with Voc (1.03 V), and good producibility compared to the pristine one was achieved in the PSCs with 0.6 wt% DA additive in the perovskite precursor.

In the present work, preparation of nickel ferrite (NiFe2O4) and its surface modification by biosynthesized Pd nanoparticles (NPs) were carried out. Firstly, NiFe2O4 NPs were synthesized via a facile combustion approach and then Pd NP biosynthesized on their surface by using an aqueous Marrubium vulgare L leaf extract. Prepared NiFe2O4 NPs were characterized by FT-IR, XRD, vibrating sample magnetometer (VSM), Field Emission Scanning Electron Microscope(FESEM), and Energy Dispersive X-ray Analysis (EDXA) techniques, in which confirmed well dispersion of spherical Pd NPs on the surface of magnetic NiFe2O4 nanoparticles. Catalytic activity of Pd/NiFe2O4 nanocomposites were evaluated in reduction of Methylene Blue (MB), Methyl Orange (MO) and Congo Red (CR) azo dyes in the presence of sodium borohydride (NaBH4). Observed results showed the reduction/decolorization times in the presence of magnetically recoverable Pd/NiFe2O4 nanocomposites were very shorter than that of NiFe2O4 catalyst.

Uranium is one of the most threatening elements due to its radioactivity and high toxicity. In the course of the nuclear fuel cycle, significant amounts of uranium are released into the environment. Biosorption technology offers the advantages of low operating costs and high efficiency in metal removal from aqueous solutions. In this work, the sorptions of uranyl ions from aqueous solutions by Saccharomyces Cerevisiae (SC) on zeolite clinoptilolite were investigated. First, a characterization of the natural zeolite was performed by classical chemical analysis and, then the influence of solution pH, temperature, contact time and, initial concentration on the sorption of uranyl was investigated. The concentration range of uranyl in the solution was between 0.02 and 1 mmol L-1, which was determined by the inductively coupled plasma optical emission spectrometry method (ICP-OES). Further results showed that metal binding occurred extracellularly at the cell wall surface and the rate of sorption of uranyl ions by free yeast cells was rapid from SC. Also, comparison of the results from BET for the primary and modified biomass shows an increase in the surface area of the modified biomass as a result of adsorption on clinoptilolite zeolite. The equilibrium adsorption ratio and distribution of uranium hydrolysis products for all samples was calculated and showed that the points corresponding to initial concentrations of less than 0.1 mmol L-1 have higher and narrower absorption fractions. Moreover, the adsorption rate decreases at concentrations higher than 0.2 mmol L-1 compared to low concentrations.