Controllable synthesis of single-crystal SnO2 nanowires and tri-crystal SnO2 nanobelts

Abstract

Depending on the nucleation sites, two types of tin dioxide (SnO₂) nanostructures were synthesized: (1) single-crystal SnO₂ nanowires and (2) novel tri-crystal SnO₂ nanobelts with the coexistence of (301) and (01) twins. It is speculated that the different vapor concentrations of Sn/O may lead to the nucleation of distinct structures and morphologies in low-dimensional SnO₂. Meanwhile, the growth direction changes in both nanowires (from [01] to [001]) and nanobelts (from [03] to [001]), which could be related to the relatively lower Sn/O ratio during the later growth stages. The thermodynamic growth processes are also discussed in terms of surface energy. These findings contribute to the intuitive understanding of the growth mechanisms in SnO₂ which may lead to the property-controlled design of next generation optical and electrical nanodevices.