Hydrogen Response of Palladium Nanoparticles and Surface Modified Films

Abstract

The interest in hydrogen sensors arises due to the safety concerns of flammable hydrogen gas. newlineHydrogen gas is highly flammable if its concentration exceeds 4 percent in air. Thus hydrogen sensors newlineare required that can detect minimal concentration of hydrogen below its limit of detection and newlineoperate at wide range of temperatures low and high needed for automotive, aerospace and fuel newlinecell applications. The advancement in developing palladium and palladium modified devices as newlinehydrogen gas sensors has accelerated over the past two decades. Palladium based devices have newlineshown excellent hydrogen sensing properties with high sensitivity and selectivity whose newlineresponse varies with the hydrogen concentration and operating temperature. In the present work, newlineefforts have been made to fabricate a hydrogen sensing device that is simple, compact, highly newlinesensitive towards hydrogen, selective, reproducible, stable and has wide operational newlinetemperaturerange compatibility. newlineUniform 9.5 nm sized palladium nanoparticles PdNPs have synthesized by polyol method by newlinereducing sodium tetracholoropalladate at 100oC with the help of ethylene glycol in the presence newlineof polyvinylpyrrolidone capping agent. This method employs simple beaker chemistry that newlineowes to the high purity product. Thin film of palladium has prepared by solution drop method on newlineglass substrates. Palladium nanoparticles and palladium films have been characterized by newlineTransmission Electron Microscopy TEM, UV vis spectroscopy, Glancing Incident angle XRay newlineDiffraction GIXRD, Atomic Force Microscopy AFM to reveal the information on size, newlinecrystallinity and surface morphology. newline newline