Controlled synthesis of PbSe nanotubes by solvothermal transformation from selenium nanotubes.

PbSe nanotubes were successfully synthesized by a reactive template approach via solvothermal transformation of trigonal selenium (t-Se) nanotubes in ethylene glycol. It was revealed that a relatively high reaction temperature (e.g., 200 degrees C), adequate ascorbic acid, and proper lead source were crucial for preparing PbSe nanotubes through shape-preserved transformation of t-Se nanotubes. Moreover, novel Se@PbSe composite nanotubes consisting of Se nanotubes covered with a PbSe sheath were obtained by shortening the reaction time and subsequent removal of the inner Se nanotubes resulted in the formation of thin-walled PbSe nanotubes (less than 20 nm in wall thickness). On the basis of the experimental observations, a plausible mechanism for the formation of PbSe nanotubes as well as Se@PbSe composite nanotubes was proposed. Furthermore, preliminary electrochemical measurements showed that the prepared PbSe nanotubes exhibited a good electrochemical activity.