Mechanisms of size-dependent shape evolution of one-dimensional nanostructure growth

The size-dependent morphological evolution of one-dimensional (1D) SnO₂ nanostructures has been observed in experiment. It was found that the shape formations of nanowire and nanobelt of SnO₂ are size dependent, i.e., the wire is favorable when the size is less than 900.3em0exnm and the belt is favorable when the size more than 900.3em0exnm, respectively, indicating that a critical size exists in the growth of SnO₂ nanostructures to determine their morphologies. The nucleation thermodynamics, growth kinetics, and morphological transition thermodynamics were established to elucidate the size-dependent morphological evolution. The theoretical predictions are consistent with experiments, suggesting that the thermodynamic driving force seems to be the physical origin of the shape evolution.