Template free synthesis of highly ordered mullite nanowhiskers with exceptional photoluminescence

An efficient method to produce highly ordered mullite nanowhiskers using B2O3-doped molten salt synthesis was reported in this work. The morphology and optical properties of the obtained nanowhiskers were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and photoluminescence (PL) spectroscopy. The results show that highly ordered mullite nanowhiskers with uniform morphology in large scale are obtained at 1000 degrees C for 3 h in air. The structure of mullite is Al-rich and single crystalline. The diameter is in the range of 90-110 nm and length up to 20-30 mu m. The reaction mechanism of the highly ordered mullite nanowhiskers is attributed to local concentration gradient. Due to the Al-rich structure, mullite nanowhiskers demonstrate strong photoluminescence (PL) emission at 399 nm, 452 nm and 468 nm, implying mullite nanowhiskers can be applied as a promising candidate in optical and electronic fields. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.