Abstract
A novel Niobium-doped SnO2 nanofibres with a complex loose-tube (fiber-in tube) morphology containing a solid fibre within a hollow shell has been prepared by conventional, single-needle electrospinning. The formation mechanism of such 1D architectures has been elucidated, showing the role of the niobium dopant in driving the morphology of electrospun tin oxide from dense fibres towards the loose-tube morphology by enhancing the Kirkendall effect where precursor salts diffuse to the fibre surface during calcination. The role of other parameters such as the heating rate and precursor concentration has also been studied, which would enable morphological control of the nanofibres through variation of these parameters which would alter the dominant mechanism of hollow fibre formation. The materials obtained have been characterized by electron microscopy, thermo-gravimetric analysis, Raman spectroscopy, XPS, and XRD. The loose-tube morphology materials have been further functionalised by depositing Pt nanoparticles prepared by a microwave assisted polyol method, where electrical conductivity and specific surface area measurements as well as accelerated corrosion tests and electrochemical measurements show that Nb doped SnO2 loose-tubes are promising electrocatalyst supports for proton exchange membrane fuel cells.