Size-controlled electrochemical synthesis and properties ofSnO2 nanotubes

Abstract

SnO2 nanotubes with controlled diameter and length were synthesized using an electrochemicalmethod at room temperature. The length and wall thickness of the nanotubesincreased monotonically with the deposition time and the diameter of thenanotubes was altered by varying the pore size of the scaffolds. Post-annealing at400 °C in dry air significantly improved the crystallinity while maintaining the nanotube structure.The temperature-dependent photoluminescence spectra indicated an activation energy of58 meV for emission centered at 410 nm. The temperature-dependent electrical resistancerevealed that the dominant electrical conduction mechanism alters from the ionization ofthe main donor centers to impurity scattering as the temperature decreases. The electricalconductance of 200 nm diameter nanotubes increased to 33 times the original value uponUV illumination at 254 nm.