Seedless Synthesis and Thermal Decomposition of Single Crystalline Zinc Hydroxystannate Cubes

Abstract

Single crystalline zinc hydroxystannate [ZnSn(OH)6] micro- and nanocubes have been successfully grown on pure tin substrates via a seedless hydrothermal synthesis method. Each ZnSn(OH)6 cube is enclosed by six equivalent {001} crystal planes. Cube size and aerial density were adjusted by controlling the reaction time and addition of diaminopropane (DAP) reagent. The hexamethylenetetramine- and DAP-assisted etching of the oxidized tin metal surface is found to play an important role in the nucleation and growth of the zinc hydroxystanate cubes. Synthesis at higher zinc nitrate concentrations as well as secondary growth resulted in the formation of ZnO nanorods in addition to the cubes. In situ scanning electron microscopy and transmission electron microscopy, thermal gravimetric analysis, and differential scanning calorimetry have been utilized to investigate the ZnSn(OH)6 thermal decomposition process. The appearance of endothermic peak near ∼540 K, attributed to the ZnSn(OH)6 decomposition, was correlated with morphology changes induced via resistive thermal annealing and localized electron beam heating.