Reversible blue light emission from self-assembled silica nanocords

Self-assembled silica nanocords were synthesized through a vapor-solid process without the assistance of catalyst. The rope-like nanostructures were formed by splitting and connecting of lots of amorphous silica nanowires. Appropriate water vapor partial pressure and reaction temperature play critical roles in determining the morphologies. Blue light emission of these nanocords can dramatically be strengthened and weakened in the process of alternative dry and humid treatments. We propose that hydroxyl groups and adsorbed-desorbed ambient water on the nanocords surface are responsible for the reversible blue light emission behavior through analyzing photoluminescence and infrared spectra. Silica nanocords with such blue light emission may be used as effective optoelectronic devices and optical signal humid sensors. (c) American Institute of Physics.