Nanochemistry Research
Volume:6 Issue: 1, Winter-Spring 2021

Owing to their enriched host-guest chemistry and high porosity, metal-organic frameworks ‎‎(MOFs) applied extensively in the detection of a large variety of hazardous chemicals, ‎especially metal ions, using different instrumental methods, such as photoluminescence. In this ‎study, two pillar-layered MOFs, [Cu2(BDC)2(DABCO)] and its amine-functionalized ‎isostructure, [Cu2(NH2-BDC)2(DABCO)], were successfully prepared to highlight the amino ‎group role in the metal ions sensing via exploiting photoluminescence-based method. These ‎materials could recognize copper(II) cations efficiently by changing the luminescent response ‎in less than 20 minutes. With increasing the concentration of Cu(II) solution, first, the ‎luminescent response changes occurred intensely, then equilibrium was reached and no more ‎changes were observed. In the presence of other metal cations, the sensors almost recognized ‎the analyte selectively. At the end of the experimental tests, the reasonable mechanism of ‎sensing was proposed using FTIR spectroscopy and PXRD patterns. They confirmed that the ‎introduction of analyte does not collapse the structure, so just the chemical interaction between ‎the walls of pores and Cu(II) ions are responsible for the purposed application.‎

CuO / ZnO@N - GQDs@NH2 nanocomposite (copper (II) oxide / zinc oxide @ Nitrogen-doped graphene quantum dots @ aminated) as superior catalyst has been applied for the synthesis of pyrimidine - trions by three-component reactions of N, N- dimethylbarbituric acid, benzaldehydes and para-methyl aniline or para-methoxy aniline under reflux condition in water. The catalyst has been characterized by SEM (scanning electron microscope), FT - IR (Fourier-transform infrared spectroscopy), XRD (X - ray powder diffraction), TGA (Thermogravimetric analysis), EDS (Energy-dispersive X-ray spectroscopy), and XPS (X - ray photoelectron spectroscopy). The best results were gained in H2O and we found the convincing results for the synthesis of pyrimidine - trions in the presence of CuO / ZnO @ N - GQDs @ NH2 nanocomposite (5 mg) under reflux conditions. This technique prepares several benefits containing green reaction conditions, great yields in concise times, the retrievable of the nanocatalyst and low nanocatalyst loading.

In this paper, quasi-rectangular Cr2O3 nanoparticles were prepared by microwave-assisted solution using Cr(NO3)2.6H2O and salicylic acid at the presence of NaOH in optimum conditions for the power of 360 W, the temperature of 50 ºC and the time duration of 30 min. The as-prepared chromium precursor was annealed in an air atmosphere at two different temperatures, 500 ºC and 600 ºC, for 3 h. Quasi-rectangular Cr2O3 nanoparticles were prepared and characterized by Fourier transform infrared (FT-IR), and ultraviolet–visible (UV-Vis) spectroscopy, X-ray diffraction analysis (XRD), Transmission electron microscopy (TEM) and Vibrating sample magnetometer (VSM). The sharp peaks in FT-IR spectra and high intensity peaks in XRD patterns confirm that the single and pure phase existence of the Cr2O3 nanoparticles with an average nanoparticle size of 25 nm. The optical band gap (Eg) values of the as-prepared Cr2O3 nanoparticles calculated were in the range of 1.6 and 1.8 eV, respectively. The TEM images revealed a highly homogeneous quasi-rectangular morphology without any agglomeration. The magnetic properties of the Cr2O3 nanoparticles show weak ferromagnetic behavior.

Because of impossibility to achieve a general column for separation purposes, columns must be amended in order to acquire specific chemical characteristics such as hydrophobic, hydrophilic or ionic interactions. In this regard, particular properties of nanoparticles such as large specific surface, high pore volume, narrow particle size- and pore size distribution, and excellent stability introduce them as perfect supports for electrochromatography and chromatographic applications, which enhance the retention and separation efficiency. On the other hand, because of disadvantages of silica stationary phases, it is noteworthy to design new stationary phases for the separation process. Apart from that, the applications of nanoparticles in separation process give rise to reach a suitable mass transfer, which is significant in chromatographic science. Hence, the present report studies various stationary phases based on the nanoparticles for the analysis of biomolecules and chiral drugs using capillary electrochromatography and liquid chromatography techniques, which provide rapid and efficient separations, short run time, high enantioseparation, and less consumption of expensive stationary phases.

Functionalized SBA -15 (Immobilization of Pd on the modified SBA -15) has been applied as an efficient catalyst for the preparation of indenopyrazolones by multi-component reactions of phenylhydrazine, aromatic aldehydes and indan-1,2,3- trione at room temperature in acetonitrile. The catalyst has been characterized by X-ray diffraction spectroscopy ( XRD ), Field emission scanning electron microscopy ( FE - SEM ), Transmission electron microscopy ( TEM ), X-Ray photoelectron spectroscopy ( XPS ), Energy-dispersive X - ray spectroscopy ( EDX ), Fourier-transform infrared spectroscopy ( FT-IR ), N2 adsorption analysis, Temperature Programmed Desorption ( TPD ), and Differential thermal analysis ( TGA - DTA ). The advantages of this method include the reusability of the catalyst, low catalyst loading, excellent yields in short reaction times and easy separation of products. Meanwhile, this recoverable catalyst will provide a regular platform for heterogeneous catalysis, green chemistry, and environmentally benign protocols in the near future.

Neutralization ability of some antiviral nanobodies was computed against the receptor binding domain (RBD) of the severe acute respiratory syndrome coronavirus 2 (SARS-COV 2). CoDockPP Server and COVID-19 Docking Server respectively was applied for a protein-protein molecular docking. The affinity of candidate nonobodies was investigated for blocking of RBD against the human angiotensin coverting enzyme 2 (ACE2). The neutralization ability of nonobodies was compared with natural nanobodies of Ty1, H11-H4, EY6A, H11-D4 and synthetic construct of Sb23, ybody MR17, sybody MR17-K99Y, and SR4 that experimentally was involved against the RBD of SARS-COV 2. It was seen, the 15 reported VHH was able for blocking with an estimated binding energy greater than -235.55 (kcal/mol) for Ty1 with the lowest affinity to the RBD. VHH 7A, VHH PVSP29F, Cameld VHH 9, VHH PVSS8A, VHH 12B, VHH 59H10, VHH PVSP6A, VHH 10E, VHH 17B and VHH 59H10 respectively was proposed for neutralization of RBD while the two last VHH are more confidence due to the greater values of affinity against -342.56 (kcal/mol) for SR4. The energy maps of ACE2, VHH 17B and VHH 59H10 was identified that hydrogen donor, steric, hydrogen acceptor and electrostatic interactions respectively were significant for blocking RBD of SARS-COV 2. This study conform structural insight for neutralization of RBD spike glycoprotein of SARS-COV 2 by nanobodies and suggest VHH that may serve as useful therapeutics during the pandemic.

Recently, the concerns about depletion of fossil fuels and also the environmental pollution arisen from burning of them have driven scientists to quest for clean and sustainable energy resources. Some advantages of hydrogen have made it as an alternative energy resource to fossil fuels. Electrochemically splitting of water is considered as one of the main techniques to produce high-purity hydrogen. Fabrication of cost-effective electrocatalysts for oxygen evolution reaction (OER) in a water splitting process is vital for large-scale practical applications. Herein, we present an affordable and straightforward method for synthesis of NiO nanoparticles supported on Ni foam for oxygen evolution reaction (OER). A single-step annealing process is carried out at the different temperatures to achieve an optimal temperature, at which an electrocatalyst with a tailored morphology and high electrocatalytic activity is obtainable. The best electrocatalytic activity is showed by the electrode fabricated at 400 °C, which delivers current density of 10 mA/cm2 at 1.59 mV potential versus reversible hydrogen electrode (RHE) under alkaline condition. Various material characterization tests accompanied by electrochemical measurements are employed to clarify the cause of the excellent electrocatalytic activity of the electrode fabricated at 400 °C.

Biochar, as a low-cost carbon obtained from barley straw, was used for the simple sol–gel synthesis of visible light photocatalysts comprising N-doped TiO2/biochar nanocomposite (N-TiO2/C) and thermally treated N-TiO2/C. The nanocomposites were characterized by SEM, EDX, TEM, XRD, BET, FTIR, DRS UV-vis, and PL measurements. The doped TiO2 catalyzed the photodegradation of rhodamine B (RhB) in aqueous dispersion under visible light illumination where the N-TiO2/C nanocomposite with a band-gap of 2.96 eV and large surface area (206 m2 g-1) showed the highest photocatalytic activity and degrading 99% of RhB under visible light of a 40-Watt white LED lamp within 105 min. Photoluminescence (PL) spectroscopy experiments revealed the effective separation of charge carriers by the N-doped TiO2 materials. The presence of carbon enhances the photocatalytic activity of N-TiO2 material by decreasing the band gap, enhancing the visible light absorption, reducing the reflection of light, enhancing the adsorption of RhB and intermediates on the N-TiO2 surface, thus prolonging the separation electrons (e-) and valence band hole (h+).

Titanium dioxide-containing hybrid nanocomposites have been considered for their various applications in semiconductors, sensors, antibacterial and hygienic materials, photocatalysts, and solar cells. In this study, a new hybrid nanocomposite containing titanium dioxide nanoparticles modified with copper metal and the organic pigment phthalocyanine was successfully synthesized and characterized. For this purpose, first titanium dioxide nanoparticles modified with copper metal were prepared by the sol-gel method. Then a new hybrid nanocomposite was synthesized using modified nanoparticles by chemical precipitation method. Characterization of modified nanoparticles and synthesized hybrid nanocomposites has been done using X-ray diffraction (XRD) analysis, FT-IR spectroscopy, EDX analysis, reflection spectroscopy, concurrent thermal analysis (TG, DTA) and Abbott electron microscopy. Our results confirm the formation of a hybrid nanocomposite containing modified titanium dioxide nanoparticles and the organic pigment phthalocyanine with pure anatase phase. TEM micrograph showed a particle size of hybrid nanocomposite of about 20 nm. The band gap of the resulting hybrid nanocomposite was 2.80 eV, which was significantly reduced compared to the pure titanium dioxide (3.17 eV). As a result, the synthesized hybrid nanocomposite is very suitable for photocatalytic, photovoltaic and super hydrophilic applications under sunlight due to its absorption edge in the visible region.

Nickel oxide /gadolinium dopped ceria nano powders, NiO/GDC, (NGC) with controlled morphology were synthesized by the sol-gel method. The nickel(II) coordination compounds have been used as new precursors for the preparation of ceramic material, NiO/GDC, as anodic powders for application in solid oxide fuel cell. The formation of diverse morphologies with different porosity was observed by varying the Nickel(II) coordination compounds, [NiL2(µ-acetylenedicarboxylate)]n, [NiL2(µ-terephthalate)]n and [NiL2(µ-2,6 pyridinedicarboxylate)]n,. Then three different kinds of nickel oxide / gadolinium dopped ceria, NGC (a), NGC (b), and NGC (c) samples of different shapes were developed by new precursors. Thiese powders have been used as electrocatalyst for solid oxide fuel cell. The catalytic performance of NGC anodes for the hydrogen oxidation reaction was analyzed via impedance spectra test using yttria-stabilized zirconia (YSZ)-supported symmetry half-cell. The modified NGC (c) anode powder fabricated with the new precursor of [NiL2(µ-2,6 pyridinedicarboxylate)]n (N’-(pyridine-3-yl)methylene)isonicotinohydrazide (L)) presented the least polarization resistivity of 0.106 Ω. cm2 measured at 800 ℃ under humidified H2. The NGC (c) anode powder with a better pore distribution and excellent microstructure demonstrated the most desirable electro-catalytic activity.

Sono-chemical is a fast procedure for preparing monodisperse nanoparticles. Magnetite nanoparticles were prepared via a sono-chemical reaction at a room temperature. Fe3O4 nanostructures were then added to acrylonitrile-butadiene-styrene (ABS) copolymer. Nanocomposites are very attractive due to the fact that small amount of nanostructure can lead to great improvement in many properties, such as mechanical and thermal property. Nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The XRD pattern of nanoparticles is indexed as a cubic phase (space group: Fd-3m). Fe3O4 nanostructures exhibit a super paramagnetic behaviour with a saturation magnetization of 54 emu/g and a coercivity of 11 Oe at room temperature. The effect of ultrasonic power on the shape and particle size was investigated and the result showed at 150W by increasing power growth stage overcome to nucleation stage and nanoparticles with bigger diameters were obtained. The flame retardancy behavior of ABS-Fe3O4 was studied by UL-94 analysis.

Dy-doped Y2O3 coated biosilica nanostructures with variable Dy3+ contents were synthesized by a facile hydrothermal technique. The products were characterized by means of energy dispersive X-ray photoelectron spectroscopy (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), UV-Vis diffuse reflectance spectroscopy, and photoluminescence spectroscopy techniques. As claimed by XRD, the particles were crystallized excellently and attributed to the cubic phase of Y2O3. The influence of substitution of Dy3+ ions into Y2O3 lattice caused a redshift in the absorbance and a decrease in the bandgap of as-prepared coated compounds. The pore volume and BET specific surface area of Dy-doped Y2O3 -coated diatomite is greater than uncoated biosilica. The sonophotocatalytic activities of as-synthesized specimens were evaluated for the degradation of Reactive Blue 19. The effect of various specifications like ultrasonic power, various scavenger, and catalyst amount was explored. The results revealed that diatomite coated with Dy3+-incorporated yttrium oxide nanoparticles can be utilized in various experimental cycles with no significant drop in photocatalytic activity.