Highly Sensitive and Selective PbTiO Gas Sensors with Negligible Humidity Interference in Ambient Atmosphere.

Three PbTiO nanostructures were synthesized using a one-step hydrothermal reaction with different TiO powders as Ti sources, and their gas-sensing properties were investigated. The sensor comprising PbTiO nanoplates (NPs) exhibited a high response (resistance ratio = 80.4) to 5 ppm ethanol at 300 °C and could detect trace concentrations of ethanol down to 100 ppb. Moreover, the sensor showed high ethanol selectivity and nearly the same sensing characteristics despite the wide range of humidity variation from 20 to 80% RH. The mechanism for humidity-independent gas sensing was elucidated using diffuse reflectance infrared Fourier transform spectra. PbTiO NPs are new and promising sensing materials that can be used for detecting ethanol in a highly sensitive and selective manner with negligible interference from ambient humidity.