Bright visible photoluminescence from nanotube titania grown by soft chemical process

Bright visible photoluminescence was observed from nanotube titania (or dehydrated nanotube titanic acid) prepared by a soft chemical process. Its photoluminescence comes from the Ti-OH complex within the tubular structure. With the improvement of the crystalline structure and the desorption of physically adsorbed water on the inner and outer surfaces of the nanotube titania by annealing below 662 K, the photoluminescence intensity is enhanced. However, the intensity decreases dramatically if the tubular structure is destroyed at higher annealing temperature, and simultaneously Ti-OH bonds within the nanotube titania are broken. Therefore, the one-dimensional tubular structure is a very important factor for nanotube titania to obtain strong photoluminescence.