Solid phase growth of tin oxide nanostructures

For the first time, single-crystalline SnO2 nanostructures comprising of nanobelts, nanowires and nanosheets have been synthesised by solid phase crystal growth from tin oxide single crystals. The product was characterised by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, transmission electron microscopy, selected area electron diffraction, and Raman spectroscopy. The procedure consisted of two stages. In the first stage, a mixture of SnO2 polyhedral single crystals attached with graphite particles were produced by heating a mixture of SnCl2 and graphite. Then, the SnO2 single crystals were grown into nanobelts, nanowires and nanosheets by further heating. The role of graphite in the process is also discussed to be the surface reduction of SnO2 into oxides with lower oxygen content which provide a driving force for surface diffusion and subsequent crystal growth of tin oxide into the one and two dimensional nanostructures. The results provide insights for both fundamental research as well as technological production of SnO2 nanostructures.

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► Single-crystalline SnO2 nanobelts, nanowires and nanosheets were synthesised.
► The process included heating a mixture of SnCl2 and graphite in air.
► The product was characterised by XRD, electron microscopy and Raman spectroscopy.
► Solid state surface diffusion was the main growth mechanism.
► The results provide fundamental insight into the technological processes.