TiO2 Nanorods Decorated with Pd Nanoparticles for Enhanced Liquefied Petroleum Gas Sensing Performance.

Development of highly sensitive and selective semiconductor-based metal oxide sensor devices to detect toxic, explosive, flammable, and pollutant gases is still a challenging research topic. In the present work, we systematically enhanced the liquefied petroleum gas (LPG) sensing performance of chemical bath deposited TiO2 nanorods by decorating Pd nanoparticle catalyst. Surface morphology with elemental mapping, crystal structure, composition and oxidation states, and surface area measurements of pristine TiO2 and Pd:TiO2 nanorods was examined by high resolution transmission electron microscopy with energy-dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and nitrogen adsorption-desorption characterization techniques. LPG sensing performance of pristine TiO2 and Pd:TiO2 nanorods was investigated in different LPG concentration and operating temperature ranges. The LPG response of 21% for pristine TiO2 nanorods is enhanced to 49% after Pd catalyst decoration with reasonably fast response and recovery times. Further, the sensor exhibited long-term stability, which could be due to the strong metal support (Pd:TiO2) interaction and catalytic properties offered by the Pd nanoparticle catalyst. The work described herein demonstrates a general and scalable approach that provides a promising route for rational design of variety of sensor devices for LPG detection.