Polymer assisted colloidal nanocrystal framework synthesis: sol-gel approach

The porous colloidal nanocrystal framework material was synthesized by sol-gel assembly followed by a self-propagation procedure. The characteristics of the synthesized nanocrystal were confirmed by advanced instruments. From the DTG analysis, the poly (vinyl alcohol) was completely degraded at 400 °C. The XRD pattern and TEM image confirmed the nanoscale crystallite size of the material. BET and SEM analysis showed the mesoporous type pore size distribution. The predictable compositional analysis was confirmed from EDX, SAED, and XPS compositional analysis. Using the HSAB theory and HRTEM image analysis the formation of local heterojunction between metal oxides was approved

Synthesis and Characterization of Ti-Fe Oxide Nanomaterials for Lead Removal

TiO2-Fe2O3 binary oxides containing different percentage of Fe2O3 were synthesized using impregnation method. The Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), and thermogravimetric with differential thermal analyzer (TG-DTA) analytical techniques were used for understanding of the physicochemical properties and well impregnation of Fe2O3 in TiO2 lattice. During adsorption study, pH of the solution, adsorbent dosage, time of contact, agitation speed, and concentration of adsorbate were optimized. From Langmuir, Freundlich, FG, D-RK, Temkin, and FH adsorption isotherm models, relatively, Langmuir isotherm model fits well. For adsorption-reaction kinetic model, pseudo-first order (PFO), pseudo-second order (PSO), and Elovich were tested and intraparticle diffusion (IPD) for adsorption-diffusion kinetic models. Out of those, the PSO fits well; this indicates that the mechanism of adsorption is under control of adsorption-reaction. The mean adsorption energy, spontaneity, and reproducibility of the adsorbent were also conducted, and all of those studies support the domination of physical adsorption mechanism

Synthesis and Characterization of PVA-Assisted Metal Oxide Nanomaterials: Surface Area, Porosity, and Electrochemical Property Improvement

The poly(vinyl alcohol)-assisted sol-gel-self-propagation route has been used for the synthesis of porous binary metal oxide nanocomposites (BMONCs) and ternary metal oxide nanocomposites (TMONCs). The effects of synthesis techniques, precursor’s type, amount of PVA loading, and precursor’s percentage were studied. The optical, chemical bonding, crystallinity, morphological, textural, and electrochemical properties of the synthesized materials were characterized by UV-vis-DRS/UV-vis, FT-IR, XRD, SEM/EDX and TEM/HRTEM/SAED, BET, and CV/EIS techniques, respectively. The porous nature of the materials was confirmed by SEM, BET, and SAED analytical techniques. Using XRD and TEM analysis, the approximate particle size of the materials was confirmed to be in the nanometer range (~7-70 nm). The EDX and HRTEM analysis was confirming the presence of predictable composition and actuality of the composites, respectively. Moving from bare ZnO to ternary nanocomposites, the great morphological, surface area, and electrochemical property enhancement was confirmed. The charge transfer capability order was obtained to be ZnO/Fe2O3/Mn2O3 > ZnO/Fe2O3 > ZnO/Mn2O3 > ZnO. The respective approximate electron transfer resistance value is 7, 25, 61, and 65 Ω. Therefore, this work can improve the toxicity towards solvent used, surface area to volume ratio, and aggregation/agglomeration problem and also enhance the charge transfer capability due to the heterojunction

Porous PVA/Zn–Fe–Mn oxide nanocomposites: methylene blue dye adsorption studies

Adsorption is one of the noble techniques for remediation of organic and inorganic pollutants. The poly (vinyl alcohol) supported sol-gel and self-propagation routes have been used for the synthesis of porous ternary metal oxides nanocomposites. The optical, chemical bonding, crystallinity, morphological, textural, and electrochemical properties of the synthesized materials were characterized by DRS-UV–vis, FT-IR, XRD, SEM/EDX and TEM/HRTEM/SAED, BET, and CV/EIS techniques, respectively. The characterization of the nanocomposites confirmed their porous nature, high surface area, and better electrochemical properties. The synthesized nanomaterials were tested for the adsorption property of methylene blue dye. Important parameters such as the amount of PVA supported ternary metal oxide nanocomposite, pH of the solution, contact time, and concentration of methylene blue dye were optimized. For further understanding of the adsorption process, the adsorption isotherms and adsorption kinetics models were used. The adsorption tests revealed the presence of the chemisorption type of the adsorption process

Synthesis of Green Copper Nanoparticles Using Medicinal Plant Hagenia abyssinica (Brace) JF. Gmel. Leaf Extract: Antimicrobial Properties

Indigenous medicinal plant of Ethiopia has been applied for the first time to investigate the synergistic influence of phytoconstituents in green copper nanoparticles (g-Cu NPs) towards the enhancement of antimicrobial properties of NPs. We report the green synthesis of Cu NPs using Hagenia abyssinica (Brace) JF. Gmel. leaf extract. The synthesized g-Cu NPs were characterized by UV-visible, UV-DRS, FT-IR, XRD, SEM, EDXA, TEM, HRTEM, and SAED techniques. The maximum absorbance, λmax, was found to be 403 nm for g-Cu NPs due to surface plasmon resonance. The energy gap, Eg of NPs, was found to be 2.19 eV. FTIR spectra confirmed the presence of polyphenols, tannins, and glycosides in the leaf extract of Hagenia abyssinica. The spectral band at 740 cm-1 is a characteristic of interaction between Cu and biomolecules of the extract. The XRD analysis revealed that the g-Cu NPs appears to be more crystalline in nature. SEM and TEM micrographs showed a mix of spherical, hexagonal, triangular, cylindrical, and irregularly shaped Cu particles. The average particle size of NPs was found to be 34.76 nm by ImageJ analysis. EDX analysis confirmed the presence of copper in the g-Cu NPs. In addition, the SAED pattern of g-Cu NPs presented concentric circular patterns for 4 major planes of crystalline copper and its oxides. The experimental and calculated d-spacing values of one of the crystal planes (111) were found to be 0.2432 nm and 0.2444 nm, respectively. The d-spacing values of 0.2444 nm and 0.2040 nm correspond to d111Cu2O and d111Cu lattice fringes, respectively. The antibacterial test conducted on E. coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis showed good zone of inhibitions 12.7, 12.7, 14.7, and 14.2 mm, respectively, proving potentiality of g-Cu NPs as a remedy for infectious diseases caused by tested pathogens

Fe-Al-Mn ternary oxide nanosorbent: Synthesis, characterization and phosphate sorption property

In the present work, nanocrystalline Fe-Al-Mn ternary oxide nanosorbent was synthesized via impregnation method. X-ray diffraction (XRD), scanning electron microscope coupled with energy dispersive x-ray spectroscopy (SEM/EDX), Brunauer–Emmett–Teller (BET) technique and Fourier transform infrared spectroscopy (FTIR) were employed to characterize the as-synthesized nanomaterials. The XRD result indicates the crystalline nature of the ternary oxide with BET surface area of 49.53 m2 g−1. The optimum operating conditions to carry out sorption study such as pH, adsorbent dose, contact time, speed of agitation and initial phosphate concentration were found to be 3, 0.1 g, 16 h, 100 rpm and 30 ppm, respectively. Both Freundlich and Langmuir isotherm models fit the equilibrium data well with the latter model providing more fit to the experimental data. Kinetic data correlated well with the pseudo-second-order and Elovich models suggesting chemisorptions as the prevailing mechanism of phosphate sorption onto the nanosorbent. Thermodynamic studies resulted negative ΔG values indicating the spontaneity of the sorption process. The Fe-Al-Mn ternary nanocomposite sorbent showed a sorption capacity of 38.46 mg g−1 at pH 3. The sorption efficiency of the nanosorbent was found to be 99.5%. This adsorbent, with large sorption capacity and efficiency, is therefore a promising adsorbent for the removal of phosphate ions from aqueous systems.ID is grateful to CSIC for her research leave at AAU and HU. The financial support from the Spanish Research Council CSIC I-COOP+-2014 (COOPB20082) is acknowledged for funding. This work has also been funded from Projects MAT2015-65767-P (MINECO) and MAT2016-77496-R (AEI/FEDER, UE). The Research and Extension Office of Haramaya University (HURG-2014-03-03), School of Graduate Studies and Chemistry Department of HU are also acknowledged.Peer reviewe