Formation of rod-like Mg(OH)2 nanocrystallites under hydrothermal conditions and the conversion to MgO nanorods by thermal dehydration

Mg(OH)2 nanorods have been successfully prepared via the hydrolysis of MgSO4 in aqueous ammonium hydroxide solution under hydrothermal conditions. Subsequent thermal decomposition of the as-prepared Mg(OH)2 nanorods produced MgO nanorods due to shape memory. The morphologies of the resultant Mg(OH)2 nanocrystallites were monitored at different periods of the hydrothermal process, which clearly revealed the formation process of the Mg(OH)2 nanorods. The morphology of the MgO product, as a dehydrated product of the rod-like Mg(OH)2 nanorods, remained similar to its precursor, Mg(OH)2. The reported method is low cost, simple and environmentally benign, thus it should be relatively easy to be scaled up for industrial production.