A Facile One-Step Hydrothermal Synthesis of Graphene/CeO2 Nanocomposite and its Catalytic Properties

2013 ◽  
Vol 747 ◽  
pp. 242-245 ◽  
Author(s):  
Manish Srivastava ◽  
Ashok Kumar Das ◽  
Partha Khanra ◽  
Nam Hoon Kim ◽  
Joong Hee Lee
Keyword(s):  
Catalytic Activity ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Cetyltrimethyl Ammonium Bromide ◽  
Xrd Pattern ◽  
Transmission Electron ◽  
One Step ◽  
Ft Ir ◽  
Cetyltrimethyl Ammonium

Graphene/CeO2 nanocomposite has been successfully prepared by directly growing CeO2 nanoparticles on graphene sheets via in-situ reduction of graphene oxide containing the metal precursor. The presence of cetyltrimethyl ammonium bromide (CTAB) results the formation of CeO2 nanoparticles with a narrow size distribution. The structural, morphological, particles size and optical properties of the synthesized products were investigated through X-ray diffraction (XRD), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FT-IR) and UVvis absorbance spectroscopy, respectively. The XRD pattern shows that graphene/CeO2 nanocomposite is highly crystalline in nature. Growth of CeO2 nanoparticles with size in range of 5-18 nm on the graphene sheet were observed by TEM measurement. Optical energy band gap was calculated to be ~3.30 eV corresponding to direct transition. The catalytic activity of the synthesized nanocomposite was investigated taking hydrazine hydrate as a model system. Significant enhancement in the peak current with respect to CeO2 was observed on graphene/CeO2 nanocomposite-based electrode demonstrating the higher catalytic activity of graphene/CeO2 nanocomposite-based electrode.

Preparation of OMMT and Light-Colored and Transparent PI/OMMT Hybrid Composite Films

2013 ◽  
Vol 634-638 ◽  
pp. 1985-1989
Author(s):  
Yun Hua Lu ◽  
Zhi Zhi Hu ◽  
Guo Yong Xiao ◽  
Yan Dong ◽  
Hai Jun Chi
Keyword(s):  
Hybrid Composite ◽  
Hybrid Composites ◽  
Composite Films ◽  
Amic Acid ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Aromatic Diamines ◽  
Cetyltrimethyl Ammonium Bromide ◽  
Ft Ir ◽  
Cetyltrimethyl Ammonium

The organo-modified montmorillonite (OMMT) was prepared from Na+montmorillonite (Na+MMT) by cation exchange with cetyltrimethyl ammonium bromide (CTMAB). The light-colored and transparent polyimide (PI) and OMMT hybrid composite films from the solution of poly(amic acid)(PAA) and various amounts (0.25, 0.50, 0.75, 1.00wt%) of OMMT in N, N-dimethylacetamide (DMAc) were prepared. The PAA was synthesized from the reaction of the alicyclic dianhydrides 1,2,3,4-cyclobutanetrtracarboxylic dianhydride (CBDA) and fluorinated aromatic diamines 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene (6FAPB). The OMMT and PI/OMMT hybrid composite films were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), UV-vis transmission spectra and solubility testing. The experimental results showed that the OMMT exhibited a 2.12nm d-spacing value. These obtained PI/OMMT hybrid composites were soluble in typical imide type polar solvent. As the OMMT contents are increased, the transparency of the PI/OMMT hybrid composite films is sacrificed slightly. These PI/OMMT hybrid films are good candidates for potential solar cell flexible substrates.

One Step Synthesis and Characterization of Zirconia-Graphene Composites

2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  
Keyword(s):  
Synthesis And Characterization ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Composite ◽  
Transmission Electron ◽  
One Step ◽  
Ft Ir ◽  
Xrd Techniques

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.

Magnetic Pd/Fe3O4 Composite: Synthesis, Structure, and Catalytic Activity

2014 ◽  
Vol 67 (10) ◽  
pp. 1387 ◽  
Author(s):  
Shi-Qiang Bai ◽  
Lu Jiang ◽  
Sheng-Li Huang ◽  
Ming Lin ◽  
Shuang-Yuan Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Reduction Process ◽  
Pd Nanoparticles ◽  
Pincer Ligands ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Thermal Stability ◽  
Transmission Electron

Composite Pd/Fe3O4 (1) was designed and synthesised by immobilization of tridentate pincer ligands with triethoxysilane groups on Fe3O4 nanoparticles, PdII complexation, and in-situ reduction process. The composite was characterised by transmission electron microscopy, scanning electron microscopy energy-dispersive X-ray spectroscopy, powder X-ray diffraction, vibrating sample magnetometer, Fourier transform infrared spectroscopy, thermogravimetric analysis, and Brunauer–Emmett–Teller analysis. The composite featured Pd nanoparticles of ~2–4 nm, exhibited good thermal stability and hydrophilic property as well as excellent catalytic activity towards the reduction of 4-nitrophenol to 4-aminophenol in water.

Direct Preparation of Ce0.8Sm0.2O1.9 Powders Oxidized With H2O2 for Low Temperature SOFCs Application

2005 ◽  
Author(s):  
Jianbing Huang ◽  
Zongqiang Mao ◽  
Bin Zhu ◽  
Lizhai Yang ◽  
Ranran Peng ◽  
...  
Keyword(s):  
Single Phase ◽  
Fluorite Structure ◽  
X Ray Diffraction ◽  
Composite Electrolyte ◽  
Xrd Pattern ◽  
Transmission Electron ◽  
Direct Preparation ◽  
Novel Method ◽  
Power Densities

A novel method was developed to prepare fine doped ceria (DCO) powders directly. Ceria doped with 20 mol. % of samarium (Ce0.8Sm0.2O1.9, SDC) was prepared by in-situ oxidization of hydroxide precipitates with H2O2 in the solutions. The resultant powder desiccated at 85°C overnight was characterized by X-ray diffraction (XRD), thermogravimetry /differential thermal analysis (TG/DTA), and transmission electron microscopy (TEM). The XRD pattern showed that the as-dried SDC powder is single phase with a cubic fluorite structure like that of pure CeO2. An anode-supported SOFC was also fabricated based on SDC and 20wt. % (62mol. %Li2CO3–38 mol. %K2CO3) composite electrolyte, LiNiO2 as cathode and NiO as anode, by cold pressing. Using hydrogen as the fuel and air as the oxidant, the I-V and I-P characteristics exhibit excellent performances and the maximum power densities are about 696, 469, 377 and 240 mWcm−2 at 650, 600, 550 and 500°C, respectively.

Synthesis and Characterization of γ-Al2O3 Nanowires by a Surfactant Assisted Precipitation Method

2014 ◽  
Vol 602-603 ◽  
pp. 93-96 ◽  
Author(s):  
Fan Cheng Meng ◽  
Cheng Liu ◽  
Xiao Lei Zhang ◽  
Hai Shen Ren ◽  
Tie Kun Jia
Keyword(s):  
Raw Materials ◽  
Sodium Aluminate ◽  
Precipitation Method ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Structure Directing Agent ◽  
Ctab Concentration ◽  
Transmission Electron ◽  
Cetyltrimethyl Ammonium ◽  
Surfactant Assisted

In this study, the γ-Al2O3 nanowires were prepared by a simple surfactant assisted precipitation method using the cetyltrimethyl ammonium bromide (CTAB) as a structure-directing agent (SDAs). Homemade sodium aluminate (NaAlO2) and H2O2 were used as raw materials. The influences of CTAB concentration and calcination temperature on the morphology of product were discussed. The obtained samples were investigated using transmission electron microscopy, X-ray diffraction analysis and TG-DSC. In the end, a possible formation mechanism of wire-like γ-Al2O3 is proposed.

A Facile Synthesis of Poly(3-octylthiophene)-Titanium Dioxide Nanocomposite Particles in Supercritical CO2

2008 ◽  
Vol 8 (9) ◽  
pp. 4743-4746 ◽  
Author(s):  
Haldorai Yuvaraj ◽  
Min Hee Woo ◽  
Eun Ju Park ◽  
Yeong-Soon Gal ◽  
Kwon Taek Lim
Keyword(s):  
Titanium Dioxide ◽  
Oxidative Polymerization ◽  
X Ray Diffraction ◽  
Photoluminescence Quenching ◽  
Tem Analysis ◽  
Ir Studies ◽  
Transmission Electron ◽  
Ft Ir ◽  
Synthesized Materials

Poly(3-octylthiophene) (P3OT)-titanium dioxide (TiO2) nanocomposite powder where TiO2 was embedded with homogeneous dispersion was synthesized by in-situ chemical oxidative polymerization of 3-octylthiophene in the presence of TiO2 nanoparticles in supercritical carbon dioxide (scCO2), using ferric chloride as the oxidant. The synthesized materials could be obtained as dry powder upon venting of CO2 after the polymerization. The composites were subsequently characterized by FT-IR spectroscopy, transmission electron microscopy (TEM), X-ray diffraction studies (XRD), thermogravimetric analysis (TGA) and photoluminescence (PL). The incorporation of TiO2 in the composite was endorsed by FT-IR studies. TGA revealed enhanced thermal stability of P3OT/TiO2 nanocomposite compared to 3-octylthiophene. TEM analysis showed that well dispersed TiO2 nanoparticles in the polymer matrix. Photoluminescence quenching increased with increasing TiO2 concentration in the composite.

Synthesis of Copper Nanohexagons and Microflowers via a Surfactant-Assisted Hydrothermal Process

2013 ◽  
Vol 785-786 ◽  
pp. 420-423
Author(s):  
Jun Jie Jing ◽  
Ji Min Xie ◽  
Gao Yuan Chen ◽  
Wen Hua Li ◽  
Ming Mei Zhang
Keyword(s):  
Hydrothermal Process ◽  
Sodium Ascorbate ◽  
Ammonium Bromide ◽  
Cu Nanoparticles ◽  
X Ray Diffraction ◽  
Cetyltrimethyl Ammonium Bromide ◽  
X Ray ◽  
Cetyltrimethyl Ammonium ◽  
Cu Nanostructures ◽  
Surfactant Assisted

A facile solution-phase process has been demonstrated for the selective preparation of single-crystalline Cu hexagons and flowers by reducing Cuprous iodide (CuI) with Sodium ascorbate (VCNa) in the presence of cetyltrimethyl ammonium chloride (CTAC) or cetyltrimethyl ammonium bromide (CTAB). The product was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). To study the formation process of Cu nanoparticles, samples obtained at various stages of the growth process were studied by XRD. UV-vis spectra of the Cu hexagons and flowers were recorded to investigate their optical properties, which indicated that as-prepared Cu nanostructures exhibited morphology-dependant optical property.

In-situ Gold Coating of Superparamagnetic Nanoparticles by Microemulsion Method

2001 ◽  
Vol 704 ◽  
Author(s):  
D. K. Kim ◽  
M. Mikhailova ◽  
M. Toprak ◽  
Y. Zhang ◽  
B. Bjelke ◽  
...  
Keyword(s):  
Superparamagnetic Iron Oxide ◽  
Superparamagnetic Nanoparticles ◽  
Ammonium Bromide ◽  
Oxide Nanoparticles ◽  
Gold Coating ◽  
Subsequent Reduction ◽  
Cetyltrimethyl Ammonium Bromide ◽  
Vis Spectroscopy ◽  
Cetyltrimethyl Ammonium

AbstractMonodispersed gold coated Superparamagnetic Iron Oxide Nanoparticles (SPION) were prepared in water-in-oil reverse microemulsion (μE) of CTAB (cetyltrimethyl -ammonium bromide)/octane/butanol/water and Brij@97/cyclohexane/water. Gold coated SPION were obtained in the μE system by coprecipitation of magnetite and subsequent reduction of Au on the surface of the magnetite using NaBH4. The SPION were characterized by TEM with EDX, AFM, TGA, ESA, UV-Vis spectroscopy, and SQUID at intermediate and final stages.

Study on Preparation and Interlayer Ion State of Fe/Ni Pillared Motmorillonite

2013 ◽  
Vol 873 ◽  
pp. 267-272
Author(s):  
Xi Xi Zhu ◽  
Li Wang ◽  
Wei Jia Gao
Keyword(s):  
Structural Changes ◽  
Interlayer Space ◽  
Fluorescence Analysis ◽  
Raw Material ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Cetyltrimethyl Ammonium Bromide ◽  
X Ray ◽  
Pillared Montmorillonite ◽  
Cetyltrimethyl Ammonium

Fe/Ni pillared montmorillonite is synthesized by precursor method. Organic pillared montmorillonite is prepared first by ion exchange with Cetyltrimethyl ammonium bromide (CTAB) using Ca-montmorillonite as raw material after pretreatment. Fe/Ni pillaring agents is prepared by copolymerization method. Then the Fe/Ni pillared montmorillonite is synthesized through ion exchanging and calcining. The structural changes and thermostability were studied through X-ray diffraction, X-ray fluorescence analysis, infrared spectroscopy and TG. analysis. The concentration of CTAB has a significant effect on interlayer space height of momtmorillonite, which can reach 3.9756nm when the concentration is 3CEC. The interlayer space height of Fe/Ni pillared montmorillonite can reach 2.4001nm when when n (Fe3+):n (Ni2+) is equal to 7:3, and it remains 1.7876nm after calcined at 400°C for 2h. This indicates that thermostability is good. Pillaring agents embedded into montmorillonite interlayer, and bonding reaction happened between the skeleton of montmorillonite ([Si4O10]n) and pillaring agents, which forms the bonding of Si-M (Fe or Ni).

Surfactant Assisted Hydrothermal Synthesis of Nano-Microsphere Titania

2014 ◽  
Vol 722 ◽  
pp. 38-41 ◽  
Author(s):  
Yun Fei Zhuang ◽  
Ya Lan Bian ◽  
Lin Jing Zhang
Keyword(s):  
Sodium Dodecyl ◽  
Rutile Phase ◽  
Ammonium Bromide ◽  
Titanium Oxides ◽  
X Ray Diffraction ◽  
Cetyltrimethyl Ammonium Bromide ◽  
X Ray ◽  
Titanium Trichloride ◽  
Cetyltrimethyl Ammonium ◽  
Surfactant Assisted

Using titanium trichloride (TiCl3) as the precursor, cetyltrimethyl ammonium bromide (CTAB), polyvinyl pyrrolidone (PVP), sodium dodecyl sulfate (SDS) as the surfactants, sodium chloride (NaCl) as the mineralizer, titanium oxides (TiO2) nanomicrospheres were synthesized at 170 °C for 24 h via hydrothermal method. Use x-ray diffraction (XRD) and scanning electron microscopy (SEM) to characterize the crystal structure and morphology of the microspheres. The results show that pure rutile phase TiO2 microspheres can be prepared with the assist of surfactant by hydrothermal treatment. The spheres were composed of radial aligned nanorods. The diameters of the rods were about 40 nm and the lengths were about 500 nm. The diameters of the TiO2 microspheres prepared using CTAB, PVP, SDS as the surfactant were among 1μm~2μm, 5μm~10μm, and 2μm~5μm, respectively.

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