Synthesis and controlled growth of monodisperse WO3·H2O square nanoplates with the assistance of malic acid

•Monodisperse WO3·H2O square nanoplates can be obtained under hydrothermal conditions.•Discussions on the formation mechanism of the WO3·H2O nanoplates was less reported.•It is proved that malic acid play an important role in the formation of square nanoplates.•This research is important for the preparations and applications of other metal oxides materials.

Monodisperse WO3·H2O square nanoplates were obtained under hydrothermal conditions with the assistance of malic acid. The morphologies and structures of the plates are characterized by the analyses of XRD, SEM and TEM. In addition, the growth mechanism of the plate-like tungsten oxides has been primarily discussed and the schematic model and crystal structure have been given out. These WO3·H2O nanoplates are revealed as orthorhombic crystal structure with exposure (010) facet. It is proved that malic acid will preferable absorb on the (010) facets during the crystal growth, leading to the growth along the crystal direction [100] and [001], and further determining the formation of plate-like WO3·H2O. This research is of great significance in the preparations, characterizations and applications of various 2D semiconductor metal oxides.

Graphical abstractMonodisperse WO3·H2O square nanoplates were obtained under hydrothermal conditions. We give a primarily discussion on the formation mechanism of the prepared WO3·H2O nanoplates with the existence of malic acid.Figure optionsDownload full-size imageDownload as PowerPoint slide