Synthesis and Humidity Sensing Properties of Sn-Doped Nano-TiO2

Abstract

Nanostructured Sn-doped TiO2 have been prepared by ball milling using SnO2 and TiO2 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 TiO2 and sintered at 800°C for 3 h. 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, TiO2—20 wt% of SnO2 possessed the highest humidity sensitivity, while the pure TiO2 and SnO2 composite possessed a low sensitivity.