| 1. |
- Amin, Sidra, et al.
(författare)
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MoSx-Co3O4 Nanocomposite for Selective Determination of Ascorbic Acid
- 2021
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Ingår i: Journal of Nanoscience and Nanotechnology. - : AMER SCIENTIFIC PUBLISHERS. - 1533-4880 .- 1533-4899. ; 21:4, s. 2595-2603
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Tidskriftsartikel (refereegranskat)abstract
- Designing a nanocomposite with sensitive and selective determination of ascorbic acid is challenging task. It is possible through the exploitation of attractive features of nanoscience and nanotechnology for the synthesis of nanostructured materials. Herein, we report the decoration of nanoparticle of MoSx on the surface of Co3O4 nanowires by hydrothermal method. The MoSx nanoparticles shared the large surface on the Co3O4 nanowires, thus it supported in the development enzyme free ascorbic acid sensor. Non-enzymatic sensor based on MoSx-Co3O4 composite was found very selective for the determination of ascorbic acid (AA) in phosphate buffer solution of pH 7.4. The MoSx-Co3O4 nanocomposite was used to modify the glassy carbon electrode to measure AA from variety of practical samples. The MoSx-Co3O4 nanocomposite was used to modify the glassy carbon electrode and it has shown the attractive analytical features such as a low working potential +0.3 V, linear range of concentration from 100-7000 mu M, low limit of detection 14 mu M, and low limit of quantification (LOQ) of 42 mu M. The developed sensor is highly selective and stable. Importantly, it was applied successfully for the practical applications such as detection of AA from grapefruit, tomato and lemon juice. The excellent electrochemical properties of fabricated MoSx-Co3O4 nanocomposite can be attributed to the increasing electro active surface area of MoSx. The presented nanocomposite is earth abundant, environment friendly and inexpensive and it holds promising features for the selective and sensitive determination of AA from practical applications. The nanocomposite can be capitalized into the wide range of biomedical applications.
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| 2. |
- Andersson, Gabriella, et al.
(författare)
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Anisotropy Tuning in Tetragonal FeCo Alloys
- 2010
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Ingår i: Journal of Nanoscience and Nanotechnology. - : American Scientific Publishers. - 1533-4880 .- 1533-4899. ; 10:9, s. 6186-6189
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Tidskriftsartikel (refereegranskat)abstract
- We review our previous work on magnetocrystalline anisotropy tuning of superlattices based on tetragonally distorted FeCo-alloys. In addition we present new experimental results on the effect of changing the composition of the FeCo alloy. The discussion is based on the separation of the magnetocrystalline anisotropy into contributions from the interfaces and strain, as well as from the composition.
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| 3. |
- Andersson, Mikael, 1988
(författare)
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Nanoparticle Magnetism: Superspin Glasses
- 2019
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Ingår i: Journal of Nanoscience and Nanotechnology. - : American Scientific Publishers. - 1533-4880 .- 1533-4899. ; 19:8, s. 4903-4910
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Tidskriftsartikel (refereegranskat)abstract
- This article discusses the magnetic super-phase, which occurs in strongly interacting magnetic nanoparticle systems. The phase is a nanoparticle analog to the atomic magnetic spin glass phase and is therefore called a superspin glass. Experimental data for a dense maghemite nanoparticle compact is presented and it is shown that this system forms a superspin glass phase by undergoing a second order phase transition. Below its transition temperature the system exhibits non-equilibrium dynamical properties similar to those of atomic spin glasses. It was shown that it is possible to tune the transition temperature by choosing the size of the particles used to make the compact. By mixing two sizes of particles (9 and 11.5 nm) and making compacts of different relative concentration of these sizes it was shown that it is the average dipolar interaction which determines the transition temperature.
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| 4. |
- Anttu, Nicklas, et al.
(författare)
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Coupling of Light into Nanowire Arrays and Subsequent Absorption
- 2010
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Ingår i: Journal of Nanoscience And Nanotechnology. - : American Scientific Publishers. - 1533-4899 .- 1533-4880. ; 10:11, s. 7183-7187
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Konferensbidrag (refereegranskat)abstract
- We present a theoretical study of the absorption of light in periodic arrays of InP nanowires. The absorption in the array depends strongly on the diameter and the length of the nanowires, as well as the period of the array. Nanowires of a length of just 2 Am are able, after an appropriate choice for the other parameters, to absorb more than 90% of the incident energy of TE and TM polarized light, with photon energies almost all the way down to the band gap energy and an incidence angle up to 50 degree. This high total absorption arises from a good coupling of the incident light into the nanowire array at the top interface between air and the array and absorption inside the array before the light reaches the interface between the nanowires and the substrate. We find that for a given photon energy there exists a critical nanowire diameter above which a dramatic increase in the absorption occurs. The critical diameter decreases for increasing photon energies, and is directly related to the dispersion of waveguiding modes in single isolated nanowires. A characterization showed that the absorption characteristics of the nanowire arrays are very promising for photovoltaic applications.
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| 5. |
- Battiston, S., et al.
(författare)
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Influence of Al and Mg Addition on Thermoelectric Properties of Higher Manganese Silicides Obtained by Reactive Sintering
- 2017
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Ingår i: Journal of Nanoscience and Nanotechnology. - : American Scientific Publishers. - 1533-4880 .- 1533-4899. ; 17:3, s. 1668-1673
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Tidskriftsartikel (refereegranskat)abstract
- Higher manganese silicides (HMS), represented by MnSix (x = 1.71-1.75), are promising p-type candidates for thermoelectric (TE) energy harvesting systems at intermediate temperature range. The materials are very attractive as they may replace lead based compounds due to their nontoxicity, low cost of starting materials, and high thermal and chemical stability. Dense pellets were obtained through fast reactive sintering by spark plasma sintering (SPS). The addition -or nanoinclusion, of Al and Mg permitted the figure of merit enhancement of the material obtained with this technique, reaching the highest value of 0.40 at 600 degrees C. Morphology, composition and crystal structure of the samples were characterized by electron microscopies, energy dispersive X-ray spectroscopy, and X-ray diffraction analyses, respectively.
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| 6. |
- Bhatti, Adeel Liaquat, et al.
(författare)
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An Efficient and Functional Fe3O4/Co3O4 Composite for Oxygen Evolution Reaction
- 2021
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Ingår i: Journal of Nanoscience and Nanotechnology. - : AMER SCIENTIFIC PUBLISHERS. - 1533-4880 .- 1533-4899. ; 21:4, s. 2675-2680
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Tidskriftsartikel (refereegranskat)abstract
- The design of efficient, stable, durable and noble metal free electro catalysts for oxygen evolution reaction (OER) are of immediate need, but very challenging task. In this study, iron induction into cobalt oxide (Co3O4) has resulted composite structure by wet chemical method. The iron impurity has brought an electronic disorder into Fe3O4/cobalt oxide composite thereby efficient oxygen evolution reaction is demonstrated. An addition of iron content into composite resulted the alternation of morphology from Nano rods to clusters of nanoparticles. The successive addition of iron into composite system reduced the onset potential of OER as compared to the pristine cobalt oxide. A Tafel slope of 80 mVdec(-1) indicates the favorable oxygen evolution reaction kinetics on the sample 4. An over-potential of 370 mV is required to reach a 10 mAcm(-2) current density which is acceptable for a nonprecious catalyst. The catalyst is highly durable and stable for 30 hours. Electrochemical impedance spectroscopy further provided a deeper insight on charge transfer resistance and sample 4 has low charge transfer resistance that supported the OER polarization curves. The sample 4 has more electrochemical active surface area of 393.5 cm(2). These obtained results are exciting and highlighting the importance of composite structure and leave a huge space for the future investigations on composite materials for energy related applications.
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| 7. |
- Bhatti, Muhammad Ali, et al.
(författare)
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TiO2/ZnO Nanocomposite Material for Efficient Degradation of Methylene Blue
- 2021
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Ingår i: Journal of Nanoscience and Nanotechnology. - : AMER SCIENTIFIC PUBLISHERS. - 1533-4880 .- 1533-4899. ; 21:4, s. 2511-2519
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Tidskriftsartikel (refereegranskat)abstract
- In this research work, we have produced a composite material consisting titanium dioxide (TiO2) and zinc oxide (ZnO) nanostructures via precipitation method. Scanning electron microscopy (SEM) study has shown the mixture of nanostructures consisting nanorods and nano flower. Energy dispersive spectroscopy (EDS) study has confirmed the presence of Ti, Zn and O as main elements in the composite. X-ray diffraction (XID) study has revealed that the successful presence of TiO2 and ZnO in the composite. The composite material exhibits small optical energy band gap which led to reduction of the charge recombination rate of electron-hole pairs. The band gap for the composite TiO2/ZnO samples namely 1, 2, 3 and 4 is 3.18, 3.00, 2.97 and 2.83 eV respectively. Small optical bandgap gives less relaxation time for the recombination of electron and hole pairs, thus favorable photodegradation is found. The degradation efficiency for the TiO2/ZnO samples for methylene blue in order of 55.03%, 75.7%, 85.14% and 90.08% is found for the samples 1, 2, 3 and 4 respectively. The proposed study of titanium dioxide addition into ZnO is facile and inexpensive for the development of efficient photocatalysts. This can be capitalized at large scale for the energy and environmental applications.
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| 8. |
- Bora, Tanujjal, et al.
(författare)
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Applications of nanotechnology in wastewater treatment-A review
- 2014
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Ingår i: Journal of Nanoscience and Nanotechnology. - : American Scientific Publishers. - 1533-4880 .- 1533-4899. ; 14:1, s. 613-626
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Tidskriftsartikel (refereegranskat)abstract
- Water on Earth is a precious and finite resource, which is endlessly recycled in the water cycle. Water, whose physical, chemical, or biological properties have been altered due to the addition of contaminants such as organic/inorganic materials, pathogens, heavy metals or other toxins making it unsafe for the ecosystem, can be termed as wastewater. Various schemes have been adopted by industries across the world to treat wastewater prior to its release to the ecosystem, and several new concepts and technologies are fast replacing the traditional methods. This article briefly reviews the recent advances and application of nanotechnology for wastewater treatment. Nanomaterials typically have high reactivity and a high degree of functionalization, large specific surface area, size-dependent properties etc., which makes them suitable for applications in wastewater treatment and for water purification. In this article, the application of various nanomaterials such as metal nanoparticles, metal oxides, carbon compounds, zeolite, filtration membranes, etc., in the field of wastewater treatment is discussed.
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| 9. |
- Bora, Tanujjal, et al.
(författare)
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Plasmonic Photocatalyst Design : Metal-Semiconductor Junction Affecting Photocatalytic Efficiency
- 2019
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Ingår i: Journal of Nanoscience and Nanotechnology. - : AMER SCIENTIFIC PUBLISHERS. - 1533-4880 .- 1533-4899. ; 19:1, s. 383-388
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Tidskriftsartikel (refereegranskat)abstract
- Silver-zinc oxide nanorods (Ag-ZnO NRs) and gold-zinc oxide nanorods (Au-ZnO NRs) plasmonic photocatalysts were fabricated by the deposition of Ag and Au nanoparticles on ZnO NRs. The photocatalysts were studied with electron microscopy, energy dispersive spectroscopy (EDS), UV-vis optical absorption and photoluminescence spectroscopy. The effect of type of metals on the ZnO surface on its photocatalytic activity under ultra violet (UV) as well as visible light excitation are investigated and their contribution towards enhanced photo-generated charge separation in terms of the type of junction (Ohmic or Schottky) the metal forms with the semiconductor are explained.
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| 10. |
- Carvalho, Alexandra T.G., et al.
(författare)
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Electronic and optical properties of chlorinated silicon nanoparticles
- 2013
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Ingår i: Journal of Nanoscience and Nanotechnology. - : American Scientific Publishers. - 1533-4880 .- 1533-4899. ; 13:2, s. 1039-1042
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Tidskriftsartikel (refereegranskat)abstract
- First-principles calculations are used to investigate the structure, electronic and optical properties of silicon nanocystals with chlorine-passivated surface. The nanocrystals considered were approximately spherical, with diameters between 1.5 and 3.0 nm. We show that the nanocrystals with chlorinated surface have a smaller bandgap, lower optical absorption threshold, and greater ionization energy and electron affinity than hydrogenated silicon nanocrystals of the same size
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