Morphology control of Nb-doped SnO₂ nanofibres formed via electrospinning: From hollow nanofibres to dense nanofibres

Nb-doped SnO₂ nanofibres (NFs) with controlled morphologies were fabricated using an electrospinning method. In particular, structures ranging from hollow to dense were formed depending on the heating rate. To achieve this morphology control, relative mole ratios of the Nb precursor to the Sn precursor of 0.007, 0.021, and 0.035 were used, and the heating rate was 0.416, 0.625, 1.25, and 5°C/min. The structural, compositional, and morphological properties of the obtained NFs were evaluated by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The succesful formation of hollow and dense Nb-doped SnO₂ NFs was found to be directly related to the use of a fast heating rate (5°C/min) and a slow heating rate (0.416°C/min), respectively. This relationship can be explained in terms of the diffusion of the ions decomposed from poly(vinypyrrolidone).