Novel methods for preparing nanocrystalline SnO 2 and Sn/SnO 2 composite by electrodeposition

Abstract

A novel process to prepare Sn/SnO 2 nanocomposite and nanocrystalline SnO 2 coating from nitrate solution by chronoamperometry and pulse technique, respectively, has been established in the present study. For the chronoamperometric technique, the percentage of Sn, ranging from 12.3 to 49.1 mol.%, can be controlled by the applied voltage (−0.2 to −0.6 V). The co-deposited metallic Sn can be oxidized into nanocrystalline SnO 2 at −0.1 V versus Ag/AgCl by using a pulse technique composed of alternatively a higher voltage stage (−0.2 to −0.6 V) and a low voltage stage (−0.1 V), and then a pure nanocrystalline SnO 2 coating can thus be synthesized. The grain size of SnO 2, ranging from 28.9 to 16.6 nm, could also be controlled by the applied voltage. The phase compositions and morphologies of the coatings were characterized by X-ray diffraction and SEM observation, respectively, and the percentage of Sn was determined by XPS analysis.