Synthesis of WO3 microfibers and their optical properties

We report a facile method to synthesize a series of WO3 microfibers with three-dimensional architectures of nanoparticles and/or microplates through an infiltration and calcination process by taking cotton as template. The crystal structures, morphologies and optical properties of the WO3 microfibers have been investigated systematically leading to the finding that the WO3 microfibers show mixed phases and delicate micro/nano-structures which can be controlled by calcination temperature and rate. Furthermore, we also find that the WO3 microfibers calcined at 500 °C under a calcination rate of 1 °C/min exhibit an intense photoluminescence emission around 452 nm.