Synthesis and Characterization of Graphene/Zinc Oxide Nanocomposites

2017 ◽  
Author(s):  
Nurettin Sezer ◽  
Adnan Ali ◽  
Muataz A. Atieh ◽  
Muammer Koc
Keyword(s):  
Zinc Oxide ◽  
Average Particle Size ◽  
Zinc Nitrate ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Nitrate Hexahydrate ◽  
Gravimetric Analysis ◽  
Impregnation Method ◽  
Materials Used

This study investigates the synthesis and characterization of graphene/zinc oxide nanocomposites. Wet impregnation method was employed for the synthesis. Firstly, graphene nanoplatelets and zinc nitrate hexahydrate were concurrently dispersed in ethanol and subjected to sonication for 1 h. Then, the dispersion was put in a furnace at 70 °C overnight. The paste was then collected and heated further up to 400 °C in air for a duration of 4 h. The process was proceeded to yield insoluble nanocomposites. The synthesis was followed by characterization of the nanocomposite samples by Field Emission Scanning Electron Microscopy (FESEM), X-Ray Diffraction (XRD) and Thermal Gravimetric Analysis (TGA). The XRD pattern revealed the presence of ZnO crystals and graphene. The FESEM images showed that ZnO crystals with average particle size of 30 nm are uniformly distributed on graphene surfaces. According to the TGA result, the content of nanocomposites is in good agreement with the materials used during synthesis.

Synthesis and Characterization of Bimetallic Fe/Co Nanocatalyst on CNTs for Fischer-Tropsch Reaction

2012 ◽  
Vol 16 ◽  
pp. 9-14 ◽  
Author(s):  
Sardar Ali ◽  
Noor Asmawati Mohd Zabidi ◽  
Duvvuri Subbarao
Keyword(s):  
Particle Size ◽  
Physicochemical Properties ◽  
Average Particle Size ◽  
Xrd Analysis ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Impregnation Method ◽  
Fischer Tropsch ◽  
Temperature Programmed

Cobalt and iron are common catalysts used in the Fischer-Tropsch (FT) reaction. This paper presents the synthesis and characterization of monometallic and bimetallic cobalt and iron nanoparticles supported on carbon nanotubes (CNTs). The CNTs-supported nanocatalysts were synthesized by a wet impregnation method at various ratios of Fe:Co. The physicochemical properties of the samples were analyzed by H2-temperature programmed reduction (TPR), CO and H2-chemisorption analyses, transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis. The effects of incorporation of Fe into Co on the physicochemical properties of Co/CNTs in terms of degree of reduction, CO and H2 chemisorptions and morphologies were investigated. TEM showed that metal nanoparticles were well dispersed on the external surface and inside the CNTs. For monometallic Co/CNTs and Fe/CNTs, the average metal particle size was 5±1 nm and 6±1 nm, respectively. For the bimetallic 70Co30Fe/CNTs nanocatalysts, the average particle size was found to be 4±1 nm. Metal particles attached to the outer walls were bigger than the ones inside the CNTs. H2-TPR analysis of Co/CNTs indicated two temperature regions at 330°C (low temperature) and 491°C (high temperature). The incorporation of iron into cobalt nanocatalysts of up to 30 % of the total metal loading enhanced the catalyst’s H2 and CO chemisorptions capacities and reducibility.

Synthesis and Characterization of Nanocrystalline ZnO Powders by a Direct Thermal Decomposition Route Using Zinc Nitrate Hexahydrate

2013 ◽  
Vol 770 ◽  
pp. 68-71 ◽  
Author(s):  
Supphadate Sujinnapram ◽  
Uraiphorn Termsuk ◽  
Atcharawan Charoentam ◽  
Sutthipoj Sutthana
Keyword(s):  
Thermal Decomposition ◽  
Crystallization Temperature ◽  
Zinc Nitrate ◽  
Zinc Nitrate Hexahydrate ◽  
Absorption Peak ◽  
Synthesis And Characterization ◽  
Nitrate Hexahydrate ◽  
Different Temperatures ◽  
Zno Powders

The nanocrystalline ZnO powders were synthesized by a direct thermal decomposition using zinc nitrate hexahydrate as starting materials. The precursor was characterized by TG-DTA to determine the thermal decomposition and crystallization temperature which was found to be at 325 oC. The precursors were calcined at different temperatures of 400, 500, and 600°C for 4 h. The structure of the prepared samples was studied by XRD, confirming the formation of wurtzite structure. The synthesized powders exhibited the UV absorption below 400 nm (3.10 eV) with a well defined absorption peak at around 285 nm (4.35 eV). The estimated direct bandgaps were obtained to be 3.19, 3.16, and 3.14 eV for the ZnO samples thermally decomposed at 400, 500, and 600°C, respectively.

Synthesis and Characterization of Water-Soluble Monolayer-Protected Gold Nanoparticles

2011 ◽  
Vol 415-417 ◽  
pp. 617-620 ◽  
Author(s):  
Yan Su ◽  
Ying Yun Lin ◽  
Yu Li Fu ◽  
Fan Qian ◽  
Xiu Pei Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Gold Nanoparticles ◽  
Average Particle Size ◽  
Water Soluble ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Transmission Electron

Water-soluble gold nanoparticles (AuNPs) were prepared using 2-mercapto-4-methyl-5- thiazoleacetic acid (MMTA) as a stabilizing agent and sodium borohydride (NaBH4) as a reducing agent. The AuNPs product was analyzed by transmission electron microscopy (TEM), UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy (FTIR). The TEM image shows that the particles were well-dispersed and their average particle size is about 5 nm. The UV-vis absorption and FTIR spectra confirm that the MMTA-AuNPs was stabilized by the carboxylate ions present on the surface of the AuNPs.

scholarly journals Investigation of structural and optical properties of biosynthesized Zincite (ZnO) nanoparticles (NPs) via an aqueous extract of Rosmarinus officinalis (rosemary) leaves

MRS Advances ◽  
2020 ◽  
Vol 5 (45) ◽  
pp. 2349-2358 ◽  
Author(s):  
S. K. Noukelag ◽  
H.E.A. Mohamed ◽  
B. Moussa ◽  
L.C. Razanamahandry ◽  
S.K.O. Ntwampe ◽  
...  
Keyword(s):  
Aqueous Extract ◽  
Surface Defects ◽  
High Surface ◽  
Average Particle Size ◽  
Zinc Nitrate ◽  
Attenuated Total Reflection ◽  
Average Particle ◽  
Nitrate Hexahydrate ◽  
Zno Nps ◽  
X Ray

AbstractBiosynthesized Zincite nanoparticles have been successfully demonstrated by a completely green process mediated aqueous extract of rosemary leaves acting as both reducing and stabilizing agents and zinc nitrate hexahydrate as the precursor. The synthesis was free of solvents and surfactants to adhere to green chemistry principles and the impartation of environmental benignity. To achieve our objective, structural and optical investigations of ZnO annealed at 500°C for 2hrs were carried-out using complementary techniques. High resolution transmission electron microscopy (HRTEM) revealed the self-assembled, highly agglomerated quasi-hexagonal shaped NPs and the average particle size was found to peak at 15.62 ± 0.22 nm. Selected area electron diffraction (SAED) and X-ray diffraction (XRD) exhibited several diffraction rings with clear diffraction spots confirming their polycrystallinity and the purity of ZnO NPs with a wurtzite structure. Furthermore, the energy dispersive X-ray spectroscopy (EDS) substantiated the presence of Zn and O in the sample and attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) illustrated the Zn-O chemical bonds. From UV-Vis-NIR, the optical band gap was amounted to 3.2 eV and photoluminescence (PL) emission spectrum to 2.9eV with high surface defects and oxygen vacancies. Through these results, the use of rosemary leaves extract is hereby shown to be a cost-effective and environmentally friendly alternative to synthesize Zincite nanoparticles (ZnO NPs).

scholarly journals Synthesis and characterization of the aluminium phosphates modified with ammonium, calcium and molybdenum by hydrothermal method

2016 ◽  
Vol 18 (2) ◽  
pp. 131-139
Author(s):  
Kinga Łuczka ◽  
Barbara Grzmil ◽  
Bogumił Kic ◽  
Krzysztof Kowalczyk
Keyword(s):  
Particle Size ◽  
Physicochemical Parameters ◽  
Average Particle Size ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Influence Of Process Parameters ◽  
Molar Ratios ◽  
Aluminum Phosphates ◽  
The Individual

Abstract Synthesis and characterization of the aluminum phosphates modified with ammonium, calcium and molybdenum were conducted. The influence of process parameters (reactive pressure and molar ratios) in the reaction mixture were studied. The contents of the individual components in the products were in the range of: 10.97–17.31 wt% Al, 2.65–13.32 wt% Ca, 0.70–3.11 wt% Mo, 4.36–8.38 wt% NH3, and 35.12–50.54 wt% P2O5. The materials obtained in the experiments were characterized by various physicochemical parameters. The absorption oil number was in the range from 67 to 89 of oil/100 g of product, the surface area was within the range of 4–76 m2/g, whereas the average particle size of products reached 282–370 nm. The Tafel tests revealed comparable anticorrosive properties of aluminum phosphates modified with ammonium, calcium, molybdenum in comparison with commercial phosphate.

Effect of pH on Zinc Oxide Powder Prepared by a Chemical Co-Precipitation Method

2010 ◽  
Vol 93-94 ◽  
pp. 691-694 ◽  
Author(s):  
Pusit Pookmanee ◽  
Issara Attaveerapat ◽  
Jiraporn Kittikul ◽  
Sukon Phanichphant
Keyword(s):  
Zinc Oxide ◽  
Average Particle Size ◽  
Ammonium Hydroxide ◽  
Zinc Nitrate ◽  
Oxide Powder ◽  
Precipitation Method ◽  
Average Particle ◽  
X Ray ◽  
Zinc Oxide Powder ◽  
Co Precipitation

Zinc oxide powder was prepared by a chemical co-precipitation method. Zinc nitrate and ammonium hydroxide were used as the starting precursors. The white precipitated powder was formed after adding ammonium hydroxide until the pH of final solution was 7-9. The powder was filtered and dried at 100 °C for 24h. The phase of zinc oxide powder was studied by X-ray diffractometer (XRD). Hexagonal single phase of zinc oxide was obtained without calcination step. The morphology of zinc oxide powder was investigated by scanning electron microscope (SEM). The particle was irregular in shape and highly agglomerated with an average particle size of 0.1 µm. The chemical composition of zinc oxide powder was determined by energy dispersive X-ray spectrometer (EDXS). The elemental composition of zinc oxide showed the characteristic X-ray energy value as follows: zinc of Lα = 1.012 keV, Kα = 8.630 keV and Kβ = 9.570 keV and oxygen of Kα = 0.525 keV, respectively.

Synthesis and Characterization of Alginate-Based Hydrogel Microbeads for Magnesium Release

2016 ◽  
Author(s):  
Shalil Khanal ◽  
Udhab Adhikari ◽  
Nava P. Rijal ◽  
Devdas Pai ◽  
Jagannathan Sankar ◽  
...  
Keyword(s):  
Particle Size ◽  
Tissue Injury ◽  
Average Particle Size ◽  
In Vitro Release ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Release Study ◽  
Vitro Release

Magnesium injection is a suitable approach for replenishment of its ions (Mg++) during neural or tissue injury and stroke to avoids risks associated with abnormally low level of Mg++ in blood. In this study, alginate encapsulated magnesium sulfate microbeads were fabricated by the electrospraying technique for Mg++ delivery. Microbeads were evaluated for particle size and surface morphology using inverted optical microscopy and scanning electron microscopy (SEM) respectively. Average particle size of 200–500 μm for hydrated and 50–200 μm for dry beads were observed. An in vitro release study of Mg++ was performed; revealing a cumulative release of ∼50% within first 24 h. This strategy can potentially be useful for the targeted local delivery of magnesium at required concentrations and subsequently enhance the therapeutic efficacy of magnesium in treating tissue injury or stroke.

Synthesis and Characterization of Zinc Oxide Nanostructures by Different Sonication Period

2014 ◽  
Vol 925 ◽  
pp. 110-114 ◽  
Author(s):  
Nurulnadia Sarip ◽  
Che Ani Norhidayah ◽  
Sharul Ashikin Kamaruddin ◽  
Farhanahani Mahmud ◽  
Siti Nooraya Mohd Tawil ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Zno Nanorods ◽  
Wide Band ◽  
Zinc Nitrate ◽  
Nitrate Hexahydrate ◽  
Zinc Oxide Nanostructures ◽  
Glass Substrates ◽  
Vis Spectroscopy ◽  
Acoustic Wave Devices

Zinc oxide (ZnO) is a wide band gap semiconductor material (3.37 eV) with numerous present applications such as varistors, surface acoustic wave devices and future biomedical applications. ZnO nanorods were grown under specific growth condition by an inexpensive and simple, chemical bath deposition method on ZnO seeded glass substrates. Study of the ZnO nanorods over different precursors, i.e zinc acetate dehydrate and zinc nitrate hexahydrate, and sonication period ranging from 0 to 120 seconds by field emission scanning electron microscope (FESEM), including the nanorod size and the surface morphology, will be demonstrated in this paper. Characterization of the ZnO film using both X-ray diffraction (XRD) and UV-Vis spectroscopy will be established in determining the optimal composition along with the optical properties, respectively.

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