Cleaner production of spherical nanostructure chromium oxide (Cr2O3) via a facile combination membrane and hydrothermal approach

Chromium oxide is widely used in national defense, hard alloy, alloy, pigment, vacuum plating, consumables and high purity alloy and belong to one of the main products of chromate production industry. In the present study, a novel cleaner process is proposed to synthesize nanostructure chromium oxide (Cr2O3) from waste source containing chromium (VI). Hydrated chromic oxide was prepared by combination membrane and hydrothermal method. After calcined, chromium (III) compound: nanostructure chromium oxide (SNCO) was obtained. In the membrane electrolyte stage, this way can reduce the amount of acid added to adjust the solution pH. Besides, addition of CO2 into the cathode compartment could improve the current efficiency and desalination efficiency, while decrease the energy consumption. Then the products were characterized. Combined with the experiment results of TGA and XRD, the potential formation mechanism of hydrated chromic oxide was proposed. The fine structure of the product was analyzed by SEM and TEM. It was proved that the nanostructure chromium oxide with good crystallinity was obtained. The UV-Vis was used for optical properties, which proved that it had good optical properties. (C) 2017 Elsevier Ltd. All rights reserved.