The Enhanced Gas Sensing Characteristics of La2O3-Doped SnO2 by the Addition of Multi Wall Carbon Nanotubes

Abstract

A La-doped SnO2 (La-SnO2) nano sol solution containing multi-wall carbon nanotubes (MWCNTs) was prepared by hydrothermal reaction and the gas sensing characteristics of the La-SnO2/MWCNT composite sensors were investigated at various heat treatment temperatures (HTTs). The MWCNTs were unaffected, partially decomposed, and completely decomposed by the heat treatment at 500, 600, and 700 degrees C in air, respectively. However, regardless of the HIT variation, the gas responses to C2H5OH al: 400 degrees C were increased 1.4-2.5 times by the addition of 0.1 wt% MWCNTs and the sensors showed selective detection to C2H5OH. The mechanisms for the enhancement of gas response are discussed in relation to the decomposition of MWCNTs and its consequent effect on the gas sensing reaction.