Camphene effect for morphological change of electrospun SnO2 nanofibres: From dense to fibre-in-hollow and to hollow nanostructures

We fabricated various morphological SnO2 nanofibres (NFs), which are controlled from dense to fibre-in-hollow and hollow nanostructures, by electrospinning with the introduction of camphene. To control the morphologies of the SnO2 NFs, the relative loading amounts of camphene to solvent were adjusted to be 0, 50, and 125 wt%. As a result, the SnO2 NFs formed at 0 wt% camphene showed a dense nanostructure due to the shrinkage effect caused by the thermal decomposition of the polyvinylpyrrolidones. For 50 wt% camphene, the SnO2 NFs formed the fibre-in-hollow nanostructure because of the occurrence of the Kirkendal effect on the surface of the as-spun SnO2 NFs. For 125 wt% camphene, the morphology exhibited a hollow nanostructure because of the occurrence of the Kirkendal effect on the entire area of the as-spun SnO2 NFs. Thus, as the loading amount of camphene was increased, the morphology of the SnO2 NFs changed from dense to fibre-in-hollow and to hollow.