scholarly journals Structural Characterization and Adsorption Properties of Dunino Raw Halloysite Mineral for Dye Removal from Water

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3676
Author(s):  
Simona Filice ◽  
Corrado Bongiorno ◽  
Sebania Libertino ◽  
Giuseppe Compagnini ◽  
Leon Gradon ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Dye Removal ◽  
Low Cost ◽  
Point Of Zero Charge ◽  
Tubular Structures ◽  
Iron Oxide Particles ◽  
X Ray ◽  
Transmission Electron ◽  
Oxide Particles ◽  
Electron Energy Loss

In this work, raw halloysite mineral from Dunino (Poland) has been characterized and tested as an efficient and low-cost adsorbent for dye removal from water. The morphology and structure of this clay were characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) and the chemical composition was evaluated by means of X-ray fluorescence spectroscopy (XRF), energy dispersive X-ray spectroscopy (EDX), and electron energy loss spectroscopy (EELS). The results showed that it is made up of both platy and tubular structures, mainly composed of Si, Al, and O. Iron oxide particles covering the platy structures were also observed. The surface charge of halloysite was measured by z-potential measurements and by the evaluation of the point of zero charge. The clay was tested as an adsorbent for the removal of positively and negatively charged dye molecules, i.e., methylene blue (MB) and methyl orange (MO), both separately and in a mixed-dye solution. Halloysite showed the ability to efficiently and selectively remove MB molecules by adsorption, both in a single-dye solution and in a mixed one. The adsorption of positive dyes on the clay surface mainly occurred through ion exchange at negatively charged sites on its surface. The possibility of regenerating the clay for further dye removal processes is also shown.

scholarly journals Economically viable synthesis of Fe3O4 nanoparticles and their characterization

2011 ◽  
Vol 13 (2) ◽  
pp. 1-5 ◽  
Author(s):  
V. Srivastava ◽  
P. Singh ◽  
C. Weng ◽  
Y. Sharma
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fourier Transform ◽  
Iron Oxide ◽  
Ammonia Solution ◽  
Bet Surface Area ◽  
Iron Oxide Particles ◽  
X Ray ◽  
Transmission Electron ◽  
Oxide Particles

Economically viable synthesis of Fe3O4 nanoparticles and their characterization Nano iron oxide particles (Fe3O4) were synthesized by coprecipitation of Fe2+ and Fe3+ by ammonia solution in the aqueous phase. Various instrumentation methods such as X ray Diffractometry (XRD), Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FTIR) spectroscopy, Brunauer-Emmett-Teller (BET) and Vibrating Sample Magnetometery (VSM) were used to characterize the properties of nanoparticles. The size of the nanoparticles was measured and was found to be between 10 to 15 nm. The value of saturation magnetization of the nanoparticles was found to be 55.26 emu/g. The BET surface area of nano iron oxide particles measured to be 86.55 m2/g.

Solution-Based Synthesis of Magnesium Oxide Nanorods

1999 ◽  
Vol 581 ◽  
Author(s):  
Q. Wei ◽  
C.M. Lieber
Keyword(s):  
Electron Microscopy ◽  
Magnesium Oxide ◽  
Magnesium Chloride ◽  
Low Cost ◽  
Industrial Applications ◽  
Transformation Process ◽  
Matrix Composites ◽  
X Ray ◽  
Transmission Electron ◽  
Oxide Nanorods

ABSTRACTA solution-based synthesis route was developed to produce large quantities of MgO nanorods. Hydrated basic magnesium chloride, which has needle-like crystal structure, was used as a precursor. A subsequent two-step transformation process with magnesium hydroxide as an intermediate product was used to preserve the morphology of the precursor to yield magnesium oxide nanorods. Scanning electron microscopy, powder X-ray diffraction and energy dispersive X-ray spectroscopy show that the products are very pure (>95%) crystalline MgO nanorods with diameters from 40 nm to 200 nm and lengths 10 microns or longer. High-resolution transmission electron microscopy and electron diffraction further reveal that these MgO nanorods are single crystals and that the rod axis is along the <110> crystal direction. A model for the structural transformation from hydrated basic magnesium chloride to magnesium oxide has been developed and compared to our experimental results. This solution-based process can be easily scaled-up, and is a low-cost source of pure magnesium oxide nanorods needed in many industrial applications, for example, as reinforcing agents in matrix composites and as flux-pinning centers in high-TC superconductors.

scholarly journals The Transport System of Nacre Components through the Surface Membrane of Gastropods

2016 ◽  
Vol 672 ◽  
pp. 103-112 ◽  
Author(s):  
Elena Macías-Sánchez ◽  
Antonio G. Checa ◽  
Marc G. Willinger
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Calcium Carbonate ◽  
Lamellar Structure ◽  
Surface Membrane ◽  
Organic Matrix ◽  
X Ray ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Electron Energy Loss

The surface membrane is a lamellar structure exclusive of gastropods that is formed during the shell secretion. It protects the surface of the growing nacre and it is located between the mantle epithelium and the mineralization compartment. At the mantle side of the surface membrane numerous vesicles provide material, and at the nacre side, the interlamellar membranes detach from the whole structure. Components of nacre (glycoproteins, polysaccharides and calcium carbonate) cross the structure to reach the mineralization compartment, but the mechanism by which this occurs is still unknown. In this paper we have investigated the ultrastructure of the surface membrane and the associated vesicle layer by means of Transmission Electron Microscopy. Electron Energy Loss Spectroscopy and Energy-dispersive X-ray Spectroscopy were used for elemental analysis. The analyses revealed the concentration of calcium in the studied structures: vesicles, surface membrane, and interlamellar membranes. We discuss the possible linkage of calcium to the organic matrix.

scholarly journals A Novel X-Ray Radiation Sensor Based on Networked SnO2 Nanowires

2019 ◽  
Vol 9 (22) ◽  
pp. 4878 ◽  
Author(s):  
Jae-Hun Kim ◽  
Ali Mirzaei ◽  
Hyoun Woo Kim ◽  
Hong Joo Kim ◽  
Phan Quoc Vuong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Low Cost ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Radiation Sensor ◽  
Sno2 Nanowires ◽  
Radiation Sensors

X-Ray radiation sensors that work at room temperature are in demand. In this study, a novel, low-cost real-time X-ray radiation sensor based on SnO2 nanowires (NWs) was designed and tested. Networked SnO2 NWs were produced via the vapor–liquid–solid technique. X-ray diffraction (XRD), transmission electron microscopy (TEM) and field emission scanning electron microscopy (SEM) analyses were used to explore the crystallinity and morphology of synthesized SnO2 NWs. The fabricated sensor was exposed to X-rays (80 kV, 0.0–2.00 mA) and the leakage current variations were recorded at room temperature. The SnO2 NWs sensor showed a high and relatively linear response with respect to the X-ray intensity. The X-ray sensing results show the potential of networked SnO2 NWs as novel X-ray sensors.

scholarly journals One-Step Synthesis of Copper and Cupric Oxide Particles from the Liquid Phase by X-Ray Radiolysis Using Synchrotron Radiation

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Akinobu Yamaguchi ◽  
Ikuo Okada ◽  
Takao Fukuoka ◽  
Mari Ishihara ◽  
Ikuya Sakurai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Synchrotron Radiation ◽  
Cupric Oxide ◽  
Oxide Particle ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
One Step ◽  
Oxide Particles

The deposition of copper (Cu) and cupric oxide (Cu4O3, Cu2O, and CuO) particles in an aqueous copper sulfate (CuSO4) solution with additive alcohol such as methanol, ethanol, 2-propanol, and ethylene glycol has been studied by X-ray exposure from synchrotron radiation. An attenuated X-ray radiation time of 5 min allows for the synthesis of Cu, Cu4O3, Cu2O, and CuO nano/microscale particles and their aggregation into clusters. The morphology and composition of the synthesized Cu/cupric oxide particle clusters were characterized by scanning electron microscopy, scanning transmission electron microscopy, and high-resolution transmission electron microscopy with energy dispersive X-ray spectroscopy. Micro-Raman spectroscopy revealed that the clusters comprised cupric oxide core particles covered with Cu particles. Neither Cu/cupric oxide particles nor their clusters were formed without any alcohol additives. The effect of alcohol additives is attributed to the following sequential steps: photochemical reaction due to X-ray irradiation induces nucleation of the particles accompanying redox reaction and forms a cluster or aggregates by LaMer process and DLVO interactions. The procedure offers a novel route to synthesize the Cu/cupric oxide particles and aggregates. It also provides a novel additive manufacturing process or lithography of composite materials such as metal, oxide, and resin.

Synthesis and characterization of tungsten oxide nanorods

2004 ◽  
Vol 19 (12) ◽  
pp. 3665-3670 ◽  
Author(s):  
D.Z. Guo ◽  
K. Yu-Zhang ◽  
A. Gloter ◽  
G.M. Zhang ◽  
Z.Q. Xue
Keyword(s):  
Electron Microscopy ◽  
Tungsten Oxide ◽  
Electric Heating ◽  
Tungsten Oxides ◽  
X Ray ◽  
Preparation Conditions ◽  
Transmission Electron ◽  
Oxide Nanorods ◽  
Electron Energy Loss

Single crystalline nanorods (15–200 nm in diameter and hundreds nanometers in length) have been formed on the carbon-covered W wires by simple electric heating under a vacuum of 5 × 10−4 Pa. The chemical composition and crystalline structure of the nanorods were carefully investigated by various characterization techniques such as scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, energy dispersive x-ray spectroscopy and electron energy loss spectroscopy. After ruling out any possible existence of carbon nanotubes (CNTs), tungsten carbide, W–Fe alloying, and formation of other types of tungsten oxides, monoclinic W18O49 phase has been well identified. The mechanism of nanorod formation of sub-tungsten oxide (∼WO2.7 compared to WO3) will be discussed in relation to the sample preparation conditions.

Fabrication of boron carbonitride (BCN) nanotubes and giant fullerene cages

2010 ◽  
Vol 88 (12) ◽  
pp. 1256-1261 ◽  
Author(s):  
Guifang Sun ◽  
Faming Gao ◽  
Li Hou
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
The Novel ◽  
X Ray Diffraction ◽  
Boron Carbonitride ◽  
X Ray ◽  
Transmission Electron ◽  
New Form ◽  
First Time ◽  
Electron Energy Loss

Boron carbonitride (BCN) nanotubes have been successfully prepared using NH4Cl, KBH4, and ZnBr2 as the reactants at 480 °C for 12 h by a new benzene-thermal approach in a N2 atmosphere. As its by-product, a new form of carbon regular hexagonal nanocages are observed. The samples are characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), transmission electron diffraction (TED), electron energy loss spectroscopy (EELS), and high-resolution transmission electron microscopy (HRTEM). The prepared nanotubes have uniform outer diameters in the range of 150 to 500 nm and a length of up to several micrometerss. The novel carbon hexagonal nanocages have a typical size ranging from 100 nm to 1.5 µm, which could be the giant fullerene cages of [Formula: see text] (N = 17∼148). So, high fullerenes are observed for the first time. The influences of reaction temperature and ZnBr2 on products and the formation mechanism of BCN nanotubes are discussed.

Novel synthesis of AlN nanowires with controlled diameters

2001 ◽  
Vol 16 (11) ◽  
pp. 3133-3138 ◽  
Author(s):  
Jun Liu ◽  
X. Zhang ◽  
Yingjiu Zhang ◽  
Rongrui He ◽  
Jing Zhu
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
High Efficiency ◽  
Low Cost ◽  
X Ray Diffraction ◽  
Synthesis Mechanism ◽  
X Ray ◽  
Novel Synthesis ◽  
Transmission Electron ◽  
New Synthesis

A relatively low-cost, high-efficiency method is reported to synthesize AlN nanowires, using carbon nanotubes as templates. The AlN nanowires were fabricated at 1100 °C, for 60 min. The diameters of the product could be roughly controlled by the sizes of carbon nanotubes selected as starting materials. The AlN nanowires obtained were among the thinnest ever known. X-ray diffraction, selected-area diffraction, energy dispersive spectroscopy, and high-resolution transmission electron microscopy, etc. were employed to characterize the products, which were found to be single crystals with some defects. The axes of the nanowires are normal to {1010} crystal planes. A new synthesis mechanism is proposed.

Structural Effects of Transition Metal Oxide Calcinations on Wurtzite Type Semiconductors That are Ferromagnetic at Room Temperature

2007 ◽  
Vol 999 ◽  
Author(s):  
Peter Moeck ◽  
Lori Noice ◽  
Chunfei Li ◽  
Amita Gupta ◽  
Rolf Erni ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Weight Percent ◽  
First Principle ◽  
Structural Effects ◽  
X Ray ◽  
First Principle Calculations ◽  
Oxide Powders ◽  
Transmission Electron ◽  
Electron Energy Loss

AbstractGallium nitride powders and zinc oxide powders were each calcined with a few weight percent of copper oxide and/or magnesium oxide either in air or N2. Powder X-ray diffractometry, transmission electron microscopy, energy dispersive X-ray spectroscopy, and electron energy loss spectroscopy were performed in order to observe calcination induced structural effects on these wurtzite type semiconductors. We note that our earlier magnetic results on Cu doped GaN are qualitatively consistent with recent first principle calculations [Wu et al., Appl. Phys. Lett. 89 (2006) 62505].

A study on the growth and structure of titania nanotubes

2004 ◽  
Vol 19 (2) ◽  
pp. 417-422 ◽  
Author(s):  
Wenzhong Wang ◽  
Oomman K. Varghese ◽  
Maggie Paulose ◽  
Craig A. Grimes ◽  
Qinglei Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Process ◽  
Alkali Treatment ◽  
Titania Nanotubes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Spectroscopy Studies ◽  
Electron Energy Loss

Titania nanotubes synthesized by a soft chemical process are described, having diameters of 8 nm to 10 nm and lengths ranging from approximately 0.1 μm to 1 μm. X-ray diffraction studies show the structure of the as-prepared nanotubes is the same as that of the starting anatase TiO2nanoparticles. Energy-dispersive x-ray analysis and electron energy loss spectroscopy studies further indicate that the as-prepared nanotubes are composed of titania. Studies using transmission electron microscopy verified that the nanotubes are formed during alkali treatment, with subsequent acidic treatments having no effect on nanotube structure and shape.

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