Synthesis and humidity sensing properties of Sn-doped nano-TiO 2

Abstract

Nanostructured Sn-doped TiO 2 have been prepared by ball milling using SnO 2 and TiO 2 as raw materials. The as-prepared powders are characterized by XRD, SEMs and EDAX to identify the structural phases, surface morphology, and composition of the materials. The materials are prepared with the addition of tin of different molar ratios (0, 0.05, 0.10, 0.15, 0.20, 0.25, and 1.0) to TiO 2 and sintered at 800°C for 3h. They are subjected to dc resistance measurements as a function of relative humidity (RH) in the range of 30%-97% in a self-designed humidity chamber, and the results revealed that the sensitivity factor increased with an increase in tin molar ratio. Among them, TiO 2-20wt% of SnO 2 possessed the highest humidity sensitivity, while the pure TiO 2 and SnO 2 composite possessed a low sensitivity. Copyright © 2011 P. Raji et al.