Sol-gel growth of titania from electrospun polyacrylonitrile nanofibres

In this paper we report on the development of TiO2 surface-residing electrospun nanofibres with controllable density of TiO2 on the support fibre surface by means of an electrospinning technique and a sol - gel process. The TiO2 precursor/PAN composite nanofibres were synthesized by electrospinning a polyacrylonitrile (PAN) solution containing TiO2 precursors. Subsequently, an immersion of the electrospun composite nanofibres in deionized water led to the hydrolysis of the TiO2 precursors. SEM, TEM and XRD pattern analyses demonstrated that TiO2 was formed and resided on the nanofibre surface. On further calcining the hydrolysed nanofibres in air at 300 degrees C, TiO2 could be conveniently converted into anatase without essentially changing the morphology of the hydrolysed nanofibres. Furthermore, surface photovoltage spectroscopy (SPS) confirmed that the TiO2 surface-residing nanofibre nonwovens had a strong SPS response. It can be attributed that the surface residence of TiO2 permits the transfer of the photogenerated electron originating from TiO2 to ITO electrodes. Potential applications of the TiO2 surface-residing nanofibres include filters, catalysis films and environmental pollution remediation films.