Asian Journal of Nanoscience and Materials
Volume:5 Issue: 2, May 2022

The synthesis of undoped and ccadmium doped Manganese Sulphide (MnS:Cd) films consists of; Manganese (ii) acetate tetrahydrate  (C4H6MnO4.4H2O), cadmium sulphate (CdSO4), and Thiourea SC(NH2)2. The electrochemical deposition (ECD) method was adopted in this research. The samples' morphological, structural, elemental, optical, and thickness were studied using appropriate techniques. The films exhibited uniform distribution of spherical balls from the morphological studies while the structural features showed crystalline peaks at (100), (002), (101, (200)) and (203) planes at 2θ (22.66, 27.77, 32.44, 36.25 and 42.80) angels. The elemental composition analysis of the deposited samples confirmed the elements deposited in the samples. For optical studies, we observed enhanced characteristics upon doping. The absorbance, transmittance, and reflectance increase as the incident radiation wavelength increases with an increase in bandgap energy from 1.8 eV – 3.6 eV. The synthesized films find potential application in photovoltaic and optoelectronics. The material thickness obtained was seen to vary directly proportionally with the energy band gap values. More so, the addition of Cd to pure MnS and increase in deposition temperature for MnS:Cd increased the thickness of the material.

In this research study, Fe3O4 nanoparticles and Fe3O4/Halloysite nanotubes (HNTs) were initially prepared for testing using a co-precipitation method. Fe3O4/HNTs/polypyrrole (PPy) core-shell magnetic nanocomposite was synthesized using in situ polymerization of pyrrole monomers at the Fe3O4/ HNT level. The Fourier transform spectrum revealed well the characteristic Halloysite and PPy peaks. Scanning electron microscopy images showed the uniform structure of nanoparticles and nanocomposite. The change in nanoparticle diameter after polymerization was well visible. Fe3O4/HNTs/PPy nanocomposites have strong acids' fine dispersion and stability properties, making them suitable for various applications. Measurement of magnetic at room temperature showed that Fe3O4 and Fe3O4/HNTs nanoparticles have a magnetic saturation of 73.84 emu/g and 30.63 emu/g, respectively. Coating the nanoparticles with PPy reduces the saturation magnetization value of Fe3O4/HNTs/PPy nanocomposites to 6.7 emu/g. Results illustrated that Fe3O4/HNTs/PPy nanocomposites have great potential for performing applications.

Post-functionalization strategy on gold nanoparticles (Au NPs) surface provides access to novel nanocomposite materials with specific physico-chemical properties for a variety of interdisciplinary applications. In this work, functionalized gold nanocomposites (Au NCs) with unique morphological features were achieved by utilizing Ruthenium(II)-polypyridyl complexes with various functional groups. They were synthesized by using ethanol/water medium at room temperature by place-exchange methodology. As the progress of binding Ru(II)-polypyridyl complex molecules, changed from ionic to covalent fashion, then Ru(II)-polypyridyl complex molecules-induced self-assembly was observed. This was evident in UV-Vis spectroscopic and TEM studies. Additionally, Ru(II)-polypyridyl complexes binding showed altered Au NPs surface with SERS enhancement at micromolar concentration level and Raman scattering signals of Au surface-bound Ru(II)-polypyridyl complexes were studied through a hot spot mechanism.

In the current study, carpobrotus edulis were used to prepare three adsorbent surfaces; (dry adsorbent material, DAM), (hot activated carbon, HAC), and (acid activated carbon, AAC), and applied for safranin dye removal as a function of pH, contact time, adsorbent dose, initial dye concentration, and temperature. The ideal pH for DAM, HAC, and AAC efficient adsorption were 7-11, 7-9, and 5-11, respectively, employing an adsorbent dosage of 0.10 g and contact time of 30, 40, and 90 min, respectively. Furthermore, the adsorption processes were better explained by the pseudo-second-order-kinetic model. It was also noticed that the safranin adsorption process demonstrated a favorable agreement with Freundlich isotherm for the three adsorbents with maximum calculated adsorption capacities of 47.49, 44.18, and 46.72 mg/g for DAM, HAC, and AAC, respectively. The results of the thermodynamic study revealed the exothermic nature of dye adsorption onto DAM and AAC and the endothermic nature onto HAC. Finally, results demonstrated that the studied surfaces are efficient adsorbents and could likely be utilized for dyes adsorption.

Amine functionalized SiO2@Fe3O4 as an efficient, green, and recyclable catalyst was synthesized using a simple approach. Then, the catalytic activity of the amine-functionalized SiO2@Fe3O4 was evaluated in the metal-free green synthesis of Knoevenagel condensation from the various aromatic aldehydes and malononitrile in water to gives the corresponding 2-(aryl) methylenemalononitrile derivatives in excellent yields with a relatively low catalyst loading. Short reaction times, commercial availability of the starting materials, being environmentally friendly, reusability of catalyst, high yields, low cost, and easy work-up are the attractive features of the present work. The reusability of the catalyst was investigated for the product 3a. After separation with an external magnet, the recycled catalyst can be reused in 7 consecutive runs. The yield of the product reduced from 97 to 91% over 7 times.

In this work, a novel urea immobilized silica-coated Fe3O4 MNP (Fe3O4@SiO2@(CH2)3-Urea) as a magnetically recoverable and metal-free nanocatalyst was designed and synthesized, and characterized using FT-IR, XRD, FE-SEM, TEM, EDX, and VSM. This system was explored in a three-component reaction to synthesize 2-amino-4H-benzo[b]pyran derivatives of dimedone, malononitrile, and aromatic aldehydes in ethanol at 80 °C. This new method has numerous merits, such as using a green and nontoxic catalyst, excellent yield, shorter reaction time, broad substrate scope, operational simplicity, and functional group compatibility. Moreover, the synthesized nanocatalyst was recovered by a magnetic field, and it was reused eight times without any appreciable change in the catalytic activity.

We report zinc oxide nanoparticles functionalized with  metallo-thoiosemicarbazones for the first time. The objective of the present work is to report the synthesis, characterization and catalytic activity of novel zinc oxide nanoparticles (ZnONPs) functionalized with copper(II) and palladium(II) complexes of 4-hydroxybenzaldehyde thiosemicarbazone (BTSC) ligand. In the present study, as-synthesized ZnONPs and itspost-functionalized ZnONPs@Cu-BTSC and ZnONPs@Pd-BTSC were prepared and analyzed using UV-visible and FT-IR, PXRD, and SEM-EDX techniques. The X-ray diffraction pattern of ZnONPs showed intense peaks indexed to (1 0 0), (0 0 2), (1 0 1), (1 0 2), (1 1 0), (1 0 3) and (1 1 2) planes which corresponded to hexagonal wurtzite  phase of  zinc oxide (ZnO) nanoparticles. The catalytic activity of ZnONPs, ZnONPs@Cu-BTSC, and ZnONPs@Pd-BTSC in reducing 4-nitrophenol was investigated. The ZnONPs@Pd-BTSC showed higher catalytic activity compared with that of the ZnONPs@Cu-BTSC.