Mechanical behavior and magnetic separation of quasi-one-dimensional SnO2 nanostructures: A technique for achieving monosize nanobelts/nanowires

The as-synthesized nanowires and nanobelts usually have a large size distribution. We demonstrate here a ball milling technique for narrowing the size distribution of oxide nanobelts and nanowires. High-resolution scanning and transmission electron microscopy reveals that the one-dimensional SnO2 nanostructures with size >150nm are sensitive to the milling effect and most of them were fractured into nanoparticles even after a short-time milling. These nanoparticles contain magnetic Fe components, which could be effectively separated from those nanobelts by employing a magnetic field. This feature promises a potentials application in the nanostructured materials separation. It was also found that the dominant size of the survived nanostructures is <100nm. The good mechanical behavior of the nanostructures are not only related to the superior mechanical toughness due to small size, but also related to the low defect density.