Gas-Sensing Properties of Needle-Shaped Ni-Doped SnO_(2) Nanocrystals Prepared by a Simple Sol-Gel Chemical Precipitation Method

摘要

The preparation of needle-shaped SnO_(2) nanocrystals doped with different concentration of nickel by a simple sol-gel chemical precipitation method is demonstrated. By varying the Ni-dopant concentration from 0 to 5 wt percent, the phase purity and morphology of the SnO_(2) nanocrystals are significantly changed. Powder XRD results reveal that the SnO_(2) doped with a nickel concentration of up to 1 wt(percent) shows a single crystalline tetragonal rutile phase, whereas a slight change in the crystallite structure is observed for samples with nickel above 1 wt(percent). High resolution scanning electron microscopy (HRSEM) results reveal the change in morphology of the materials from spherical, for SnO_(2), to very fine needle-like nanocrystals, for Ni-doped SnO_(2), annealed at different temperatures. The gas sensing properties of the SnO_(2) nanocrystals are significantly enhanced after the nickel doping.