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Showing papers on "Chromium(III) oxide published in 2018"


Journal ArticleDOI
31 Dec 2018
Abstract: Nanoparticles are nanosized clusters with dimensions less than 100nm. Nanoparticles are fabricated by physical, chemical, and biological methods. Physical and chemical methods are energy intensive and involve hazards of contaminations. Biological synthesis of nanoparticles is environment friendly, less toxic and cost effective process. Plants, microorganisms, and biomolecules are commonly exploited species for merging of nanoparticles in this method. In present work we synthesize Chromium oxide nanoparticles by biological method using fungal extract of Aspargillus Niger. The synthesized nanoparticles are characterized by XRD (X-Ray Diffraction), SEM (Scanning Electron Microscopy) and UV-Vis (Ultraviolet Visible) techniques.

14 citations



Journal ArticleDOI
TL;DR: An arc ion plating method was introduced for the deposition of chromium oxide (Cr2O3) on a steel wire substrate, and its use as a coating for solid phase microextraction with high mechanical strength, stability, and long operational lifetime.
Abstract: The authors introduce an arc ion plating method for the deposition of chromium oxide (Cr2O3) on a steel wire substrate, and its use as a coating for solid phase microextraction. The coating has a micro- and nano-scaled structure after annealing at 700 °C. It is found that Cr2O3 exhibits a good extraction capability for the aromatic hydrocarbons naphthalene, anthracene, fluorene, fluoranthene, and biphenyl. Following desorption by high temperature at 300 °C, the analytes were quantified by gas chromatography (GC). The limits of detection are in the range between 20 and 200 ng·L−1, and calibration plots are linear within a wide range (0.2 to 400 μg·L−1). The coating has excellent mechanical properties, with a hardness is as high as 31.7 GPa, and the adhesion strength between coating and substrate reaches 20.1 N (corresponding to the critical Hertzian contact stress of 10 GPa). This, along with the chemical and thermal stability of the Cr2O3 coating, endows the wire with a long operational life. It was used for at least 100 times without any obvious decline of extraction capability.

9 citations


Journal ArticleDOI
TL;DR: In this article, the effect of chromium oxide on the electric properties of a solid-oxide fuel cell electrolyte was studied and it was found that the chromium reduction at the electrolyte surface dominates when chromium is adsorbed from gas phase.
Abstract: To study the effect of chromium oxide on the electric properties of Ce0.9Gd0.1O2, a solid-oxide fuel cell electrolyte, two approaches were used: (a) the studying of electrochemical properties of the Ce0.9Gd0.1O2- electrolyte after the spontaneous adsorption of chromium-containing molecules from a gas phase and (b) the analyzing of transport properties of the Ce0.9Gd0.1O2-based chromium-containing compositions obtained by the mixing of solid-oxide electrolyte with chromium(III) oxide. It was found that the chromium reduction at the electrolyte surface dominates when chromium is adsorbed from gas phase. Both approaches allow concluding that the chromium presence in Ce0.9Gd0.1O2 deteriorates the electrolyte transport properties at temperatures above 735°С. This is caused by the chromium incorporation into the electrolyte’s fluorite structure, as well as surface microheterogeneity induced by the chromium presence at the Ce0.9Gd0.1O2 surface and the cerium and gadolinium cation redistribution between the grains’ bulk and surface. At intermediate temperatures (below 735°С) the electric conductivity of the Ce0.9Gd0.1O2-based chromium-containing composition exceeds that of the initial solid-oxide electrolyte, which can be due to changes in transport properties of the chromium-containing phases formed at the Ce0.9Gd0.1O2 surface and grain boundaries.

1 citations