Trisodium citrate assisted morphological evolution of α-MoO3 via a facile hydrothermal route and its application to improve the corrosion resistance of zinc coating

A facile trisodium citrate-assisted hydrothermal route was demonstrated for the synthesis of α-MoO3 nanostructures. Trisodium citrate concentration-dependent morphological evolution of α-MoO3 was achieved in hydrothermal process. The morphological evolution from nanorods to nanoplates was observed with increase in trisodium citrate concentration, owing to its shape directing effect by hindering the growth of α-MoO3 crystal along [001] direction. The time-dependent hydrothermal experimental results suggested that the formation and growth of α-MoO3 nanorods proceed through ‘Ostwald ripening-splitting’ mechanism. The synthesised α-MoO3 nanorods were successfully used to produce Zn – α-MoO3 coatings on mild steel using an acid sulphate bath, and the corrosion behaviour of the generated coatings was also investigated.