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chromium-oxides
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Investigation and Fabrication of Cr2O3 Thin Film Coating on Soda Lime and Low Carbon Steel Substrate
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor)
Abstract
Chromium oxide coatings (Cr2O3) have been widely used due to their remarkable properties in corrosion, wear, optical and mechanical applications. So far, several methods have been used to prepare Cr2O3 thin films. In this study, the chromium oxide was produced by the sol-gel method and dip coated on the low carbon steel and glass substrates. In this context, we encountered with the problem of incoherency of the Cr2O3 ceramic coating to the steel substrates. It is highly likely that this problem be due to causes such as: a) thermal stresses due to the difference between the thermal expansion coefficients of the substrate and the coating, b) incoherent substrate/coating interface due to their...
Ternary nanostructures of Cr2O3/graphene oxide/conducting polymers for supercapacitor application
, Article Journal of Electroanalytical Chemistry ; Volume 823 , 2018 , Pages 505-516 ; 15726657 (ISSN) ; Shahrokhian, S ; Iraji Zad, A ; Sharif University of Technology
Abstract
In this work, nanostructured composites of Cr2O3-graphene oxide (Cr2O3/GO) with conducting polymers; polyaniline (PANI) and polypyrrole (PPy) with the shape of cauliflower were synthesized via s simple and low cost one-step chronoamperometry method. The structures and morphologies of the resulting ternary nanocomposites were characterized by using Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The electrochemical capacitive properties of the prepared nanocomposites were evaluated by using cycle voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The...
The Fabrication of Copper base Chromium Oxide Reinforced Nanocomposite and Investigation of its Mechanical and Physical Properties
, M.Sc. Thesis Sharif University of Technology ; Pourazarang, Kazem (Supervisor) ; Abachi, Parvin (Supervisor)
Abstract
It is well known that Cu/Al2O3 nanocomposites have high potential for use in structural, electrical applications which enhanced mechanical characteristics are required. In the present work, in order to improve the in-situ oxidation kinetic of solute element, chromium was used instead of aluminum. At the initial stage, elemental Cu and Cr powders were mechanically alloyed for 60h under argon atmosphere. It was followed by mechanically milling of Cu-Cr pre-alloyed and Cu2O powders. The nanocomposite specimens, containing different amounts of Cr2O3, depending on the Cr content in the range of 1-3 wt. %, were produced by in-situ oxidation of Cu-Cr pre-alloyed powders. To prevent oxidation of...
Direct conversion of inorganic complexes to platinum/thin oxide nanoparticles decorated on MOF-derived chromium oxide/nanoporous carbon composite as an efficient electrocatalyst for ethanol oxidation reaction
, Article Journal of Colloid and Interface Science ; Volume 555 , 2019 , Pages 655-666 ; 00219797 (ISSN) ; Rezaee, S ; Shahrokhian, S ; Amini, M. M ; Sharif University of Technology
Academic Press Inc
2019
Abstract
In this work, we present the design and fabrication of a novel nanocomposite based on noble metal and metal oxide nanoparticles dispersed on highly porous carbon obtained via the pyrolysis of an inorganic complex and metal-organic frameworks. This nanocomposite is prepared by a two-step procedure: first, the composite support of nanoporous carbon (NPC) is obtained by the direct carbonization of the Cr-benzene dicarboxylic ligand (BDC) MOF in an Argon atmosphere at 500 °C (Cr2O3-NPC). A mixture containing Cr2O3-NPC and [PtCl(SnCl3)(SMe2)2] is then prepared, and underflow of Argon is heated to 380 °C. Finally, Pt-SnO2 nanoparticles are loaded on the Cr2O3-NPC support, and the obtained...