Fabrication of tubular magnesium oxide nanocrystals via combining ammonium sulfate leaching and precipitation method and it's crystal growth behavior

Tubular magnesium oxide (Mg0) nanocrystals were fabricated via combining ammonium sulfate leaching and precipitation method with calcined dolomite (CaCO3.Mg0) as magnesium source. The relationship between (NH4)(2)S0(4)/Mg0 molar ratio, volume of distilled ammonia and dosage of calcined dolomite and the leaching rate of magnesium were investigated, and the highest value of 96.81% for leaching rate was obtained by optimizing leaching conditions. The tubular Mg0 nanocrystals were synthesized by precipitation and calcination process, which were characterized by XRD, FT-IR, SEM and TEM. After calcination process, the crystallite size of MgO nanocrystals varies from 12.4 nm to 42.2 nm with the calcination temperature increases from 500 degrees C to 1000 degrees C. The activation energy for crystal growth of MgO nanocrystals is about 10.69 1.13 kJ/mol before 650 C, while it increases to about 27.02 +/- 0.95 kJ/mol after 650 degrees C. (C)2017 Published by Elsevier B.V.