Nano-Iron Oxides Used for Environmental Applications

2013 ◽  
Vol 583 ◽  
pp. 3-8
Author(s):  
Andrei Predescu ◽  
Ecaterina Matei ◽  
Andra Mihaela Predescu ◽  
Andrei Berbecaru ◽  
Liana Vladutiu

The paper emphasizes the importance of use the nano-iron oxides as treatment materials for wastewaters decontamination, having in mind the size of these compounds and specific surface area suitable for retaining toxic metals such as chromium or cadmium presented as major pollutants for industrial wastewaters. Also, the magnetic properties of the nano-iron oxides offer the possibility of a fast removal of these from the system, after wastewaters treatment. The obtaining of some core-shell composites with nano-iron oxides as core represent an advantage because of the dissolving tendency of the nano-iron oxides under acidic conditions, the situation being common to the industrial wastewaters.

2016 ◽  
Vol 6 (9) ◽  
pp. 3238-3252 ◽  
Author(s):  
Sumit Chabri ◽  
Arnab Dhara ◽  
Bibhutibhushan Show ◽  
Deepanjana Adak ◽  
Arijit Sinha ◽  
...  

Mesoporous and core–shell like (p)CuO–(n)ZnO nanocomposites were prepared using microstructural refinement and solid state reactions, which showed enhanced photochemical and electrochemical performances.


2012 ◽  
Vol 463-464 ◽  
pp. 543-547 ◽  
Author(s):  
Cheng Feng Li ◽  
Xiao Lu Ge ◽  
Shu Guang Liu ◽  
Fei Yu Liu

Core-shell structured hydroxyapatite (HA)/meso-silica was prepared and used as absorbance of methylene blue (MB). HA/meso-silica was synthesized in three steps: preparation of nano-sized HA by wet precipitation method, coating of dense silica and deposition of meso-silica shell on HA. As-received samples were characterized by Fourier transformed infare spectra, small angle X-ray diffraction, nitrogen adsorption-desorption isotherm and transmission electron microscopy. A wormhole framework mesostructure was found for HA/meso-silica. The specific surface area and pore volume were 128 m2•g-1 and 0.36 cm3•g-1, respectively. From the adsorption isotherm, HA/meso-silica with the great specific surface area exhibited a prominent adsorption capacity of MB (134.0 mg/g) in comparison with bare HA (0 mg/g). This study might shed light on surface modification of conventional low-cost adsorbents for removal of organic pollutants from aqueous solutions.


2018 ◽  
Vol 6 (47) ◽  
pp. 24603-24613 ◽  
Author(s):  
Xing Zhou ◽  
Xiaohui Li ◽  
Dejian Chen ◽  
Danyang Zhao ◽  
Xintang Huang

Ultrathin layered double hydroxide (LDH) nanosheets are a promising candidate as the electrode material for energy storage due to the ultrafast mass diffusion and greater specific surface area.


2014 ◽  
Vol 633-634 ◽  
pp. 451-454
Author(s):  
Quan Xiao Liu ◽  
Dan Xi Li

SEM and Automated Surface Area & Pore Size Analyzer were used to characterize surface morphology and specific surface area and the pore size distribution of fibers. The results showed that specific surface area and pore size distribution increase after ultrasonication. The ash content of the composites of ultrasonic treated fiber is larger than the untreated fiber, and the magnetic properties show a good superparamagnetic behavior.


2010 ◽  
Vol 20 (5) ◽  
pp. 945-952 ◽  
Author(s):  
Yanyan Sun ◽  
Guangbin Ji ◽  
Mingbo Zheng ◽  
Xiaofeng Chang ◽  
Shandong Li ◽  
...  

RSC Advances ◽  
2016 ◽  
Vol 6 (53) ◽  
pp. 47530-47535 ◽  
Author(s):  
Long Pan ◽  
Meng-Ying Xu ◽  
Zi-Lu Liu ◽  
Bi-Bai Du ◽  
Kun-Hao Yang ◽  
...  

A novel type of porous magnetic microsphere (Fe3O4@HCP) was firstly synthesized and possesses a high Brunauer–Emmett–Teller specific surface area and excellent adsorption capacity for organic dyes.


2011 ◽  
Vol 688 ◽  
pp. 245-249 ◽  
Author(s):  
Zhi Qiang Wei ◽  
Xiao Yun Wang ◽  
Hua Yang

Special carbon encapsulated Fe core-shell nanoparticles with a size range of 15–40 nm were successfully prepared via confined arc plasma method. The composition, morphology, microstructure, specific surface area, particle size of the product by this process were characterized via X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray energy dispersive spectrometry (XEDS) and BET N2adsorption. The experiment results shown that the carbon encapsulated Fe nanoparticles with clear core-shell structure, the core of the particles is body centered cubic (BCC) structure Fe, and the shell of the particles is disorder carbons. The particle size of the nanocapsules ranges from 15 to 40nm,with an averaged value about 30nm, the particles diameter of the core is about 16nm and the thickness of the shells is about 6-8 nm, and the specific surface area is 24 m2/g.


Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2052
Author(s):  
Ian Clark ◽  
Jacob Smith ◽  
Rachel L. Gomes ◽  
Edward Lester

Core-shell Zinc Oxide/Layered Double Hydroxide (ZnO@LDH) composite nanomaterials have been produced by a one-step continuous hydrothermal synthesis process, in an attempt to further enhance the application potential of layered double hydroxide (LDH) nanomaterials. The synthesis involves two hydrothermal reactors in series with the first producing a ZnO core and the second producing the Mg2Al-CO3 shell. Crystal domain length of single phase ZnO and composite ZnO was 25 nm and 42 nm, respectively. The ZnO@LDH composite had a specific surface area of 76 m2 g−1, which was larger than ZnO or Mg2Al-CO3 when produced separately (53 m2 g−1 and 58 m2 g−1, respectively). The increased specific surface area is attributed to the structural arrangement of the Mg2Al-CO3 in the composite. Platelets are envisaged to nucleate on the core and grow outwards, thus reducing the face–face stacking that occurs in conventional Mg2Al-CO3 synthesis. The Mg/Al ratio in the single phase LDH was close to the theoretical ratio of 2, but the Mg/Al ratio in the composite was 1.27 due to the formation of Zn2Al-CO3 LDH from residual Zn2+ ions. NaOH concentration was also found to influence Mg/Al ratio, with lower NaOH resulting in a lower Mg/Al ratio. NaOH concentration also affected morphology and specific surface area, with reduced NaOH content in the second reaction stage causing a dramatic increase in specific surface area (> 250 m2 g−1). The formation of a core-shell composite material was achieved through continuous synthesis; however, the final product was not entirely ZnO@Mg2Al-CO3. The product contained a mixture of ZnO, Mg2Al-CO3, Zn2Al-CO3, and the composite material. Whilst further optimisation is required in order to remove other crystalline impurities from the synthesis, this research acts as a stepping stone towards the formation of composite materials via a one-step continuous synthesis.


Nanoscale ◽  
2016 ◽  
Vol 8 (9) ◽  
pp. 5313-5326 ◽  
Author(s):  
Yilin Zhao ◽  
Chengran Tao ◽  
Gang Xiao ◽  
Guipeng Wei ◽  
Linghui Li ◽  
...  

Based on the synergistic photocatalytic activities of nano-sized TiO2and Ag, as well as the magnetic properties of Fe3O4, a sea urchin-like Fe3O4@TiO2@Ag nanocomposite (Fe3O4@TiO2@Ag NCs) is controllably synthesized with tunable cavity size, adjustable shell layer of TiO2nanofiber, higher structural stability and larger specific surface area.


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