Photoluminescent properties of boehmite whisker prepared by sol-gel process

A boehmite whisker powder with the aspect ratio and mean diameter of 10–40 and 2–6 nm was prepared by the sol-gel process using aluminum alkoxide as precursor. The main absorption bands located at 234 (5.31 eV), and 254.5 (4.88 eV) nm are presented in the excitation spectrum of sample. It is observed that all the spectra show two main broad bands emission whose maximum shows a large shift, which depends on the excitation wavelength. It is suggested that the ultraviolet photoluminescence emission in boehmite whisker prepared by the sol-gel process may be associated with anionic vacancies (F and F+ centers, or grouping of these two types of defects), and the non-bridging oxygen hole center (NBOHC)=Al–Oradical dot.