Synthesis and characterization of ZnO nanostructures using palm olein as biotemplate

Background: A green approach to synthesize nanomaterials using biotemplates has been subjected to intense research due to several advantages. Palm olein as a biotemplate offers the benefits of eco-friendliness, low-cost and scale-up for large scale production. Therefore, the effect of palm olein on morphology and surface properties of ZnO nanostructures were investigated. Results: The results indicate that palm olein as a biotemplate can be used to modify the shape and size of ZnO particles synthesized by hydrothermal method. Different morphology including flake-, flower- and three dimensional star-like structures were obtained. FTIR study indicated the reaction between carboxyl group of palm olein and zinc species had taken place. Specific surface area enhanced while no considerable change were observed in optical properties. Conclusion: Phase-pure ZnO particles were successfully synthesized using palm olein as soft biotemplating agent by hydrothermal method. The physico-chemical properties of the resulting ZnO particles can be tuned using the ratio of palm olein to Zn cation

Triphasic Nature of Polymers of Intrinsic Microporosity (PIM-1 and PIM-PY) Induces Storage and Catalysis Effects in Hydrogen and Oxygen Reactivity at Electrode Surfaces

Hydrogen oxidation and oxygen reduction are two crucial energy conversion reactions, which are shown to be both strongly affected by the presence of intrinsically microporous polymer coatings on electrodes. Polymers of intrinsic microporosity (PIMs) are known to possess extremely high internal surface area and ability to bind gases under dry conditions. It is shown here that both, hydrogen‐ and oxygen gas binding into PIMs, also occurs under wet or “triphasic” conditions in aqueous electrolyte environments (when immersed in 0.01 M phosphate buffer at pH 7). For two known PIM materials (PIM‐1 and PIM‐PY), nanoparticles are formed by an anti‐solvent precipitation protocol and then cast as a film onto platinum or glassy carbon electrodes. Voltammetry experiments reveal evidence for hydrogen and oxygen binding. Both, PIM‐1 and PIM‐PY, locally store hydrogen or oxygen gas at the electrode surface and thereby significantly affect electrocatalytic reactivity. The onset of oxygen reduction on glassy carbon is shifted by 0.15 V in the positive direction

Preparation of zinc oxide nano- and micro-structures using hydrothermal-template method and their applications

Pure zinc oxide (ZnO) was successfully synthesized using various non bio- and biotemplates namely, sodium dodecyl sulfate (SDS), cetyl trimethylammonium bromide (CTAB), palm olein (PO), uncooked- and cooked rice. ZnO nano- and microstructures were synthesized through hydrothermal method. The physicochemical properties of the resulting samples were characterized for samples synthesized at various amount of templates to zinc precursor. Different morphologies such as flower-, rod-, flake-, sphere-rose-, triangular- and star-like shapes were obtained. Moreover, an enhancement in BET surface area and modification in pore texture were also observed. This modification resulted from either increasing the pore size and volume or the uniformity of the pores. However, optical properties like UV-Vis absorption and band gap energy are generally quite similar to that of ZnO synthesized without templating agents. Last but not least, we also investigated the effect of the addition of the as synthesized ZnO nanoparticles into polysulfone/zinc oxide mixed matrix membranes (PSf-MMMs) for the application of gas separation. The results indicated an improvement in CO2/CH4 separation and permeance properties of PSf/ZnO MMMs

Hydrogen Storage in Polymers of Intrinsic Microporosity (PIMs)

Thesis (PhD Doctorate)Doctor of Philosophy (PhD)School of Environment and ScScience, Environment, Engineering and TechnologyFull Tex

Biotemplated Synthesis of Anatase Titanium Dioxide Nanoparticles via Lignocellulosic Waste Material

Anatase titanium dioxide nanoparticles (TiO2-NPs) were synthesized by sol-gel method using rice straw as a soft biotemplate. Rice straw, as a lignocellulosic waste material, is a biomass feedstock which is globally produced in high rate and could be utilized in an innovative approach to manufacture a value-added product. Rice straw as a reliable biotemplate has been used in the sol-gel method to synthesize ultrasmall sizes of TiO2-NPs with high potential application in photocatalysis. The physicochemical properties of titanium dioxide nanoparticles were investigated by a number of techniques such as X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, thermogravimetric analysis (TGA), ultraviolet visible spectra (UV-Vis), and surface area and pore size analysis. All results consensually confirmed that particle sizes of synthesized titanium dioxide were template-dependent, representing decrease in the nanoparticles sizes with increase of biotemplate concentration. Titanium dioxide nanoparticles as small as 13.0 ± 3.3 nm were obtained under our experimental conditions. Additionally, surface area and porosity of synthesized TiO2-NPs have been enhanced by increasing rice straw amount which results in surface modification of nanoparticles and potential application in photocatalysis

Effects of synthetic explanatory variable on saturation magnetization of colloidal nanomagnetite slurry

In this contribution, stable nanomagnetite slurry have been successfully prepared by coprecipitation method. The synthesis parameters, such as reaction temperature, heating time, surfactant concentration and precipitating agent addition rate affected magnetic properties of synthetic nanomagnetite slurries were also investigated. We discovered the optimum reaction parameters based on the highest saturation magnetization obtained under our experimental condition to disperse magnetite nanoparticles in the aqueous medium using dodecanoic acid as a surfactant. The highest saturation magnetization was achieved when 0.5:1 mole ratio of dodecanoic acid to magnetite was used and NH4OH with an addition rate of 5 ml min(-1) was added to the solution while time and temperature for heating were 45 min at 80 degrees C. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved