title: Gas sensing properties of conducting polymer/Au-loaded ZnO nanoparticle composite materials at room temperature.
abstract: In this work, a new poly (3-hexylthiophene):1.00 mol% Au-loaded zinc oxide nanoparticles (P3HT:Au/ZnO NPs) hybrid sensor is developed and systematically studied for ammonia sensing applications. The 1.00 mol% Au/ZnO NPs were synthesized by a one-step flame spray pyrolysis (FSP) process and mixed with P3HT at different mixing ratios (1:1, 2:1, 3:1, 4:1, and 1:2) before drop casting on an Al2O3 substrate with interdigitated gold electrodes to form thick film sensors. Particle characterizations by X-ray diffraction (XRD), nitrogen adsorption analysis, and high-resolution transmission electron microscopy (HR-TEM) showed highly crystalline ZnO nanoparticles (5 to 15 nm) loaded with ultrafine Au nanoparticles (1 to 2 nm). Film characterizations by XRD, field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray (EDX) spectroscopy, and atomic force microscopy (AFM) revealed the presence of P3HT/ZnO mixed phases and porous nanoparticle structures in the composite thick film. The gas sensing properties of P3HT:1.00 mol% Au/ZnO NPs composite sensors were studied for reducing and oxidizing gases (NH3, C2H5OH, CO, H2S, NO2, and H2O) at room temperature. It was found that the composite film with 4:1 of P3HT:1.00 mol% Au/ZnO NPs exhibited the best NH3 sensing performances with high response (approximately 32 to 1,000 ppm of NH3), fast response time (4.2 s), and high selectivity at room temperature. Plausible mechanisms explaining the enhanced NH3 response by composite films were discussed.
authors.affiliation: Program in Materials Science, Faculty of Science, Maejo University, Chiang Mai 50290, Thailand.
authors.forename: Viruntachar
authors.initials: V
authors.lastname: Kruefu
authors.affiliation: National Electronics and Computer Technology Center, Pathumthani 12120, Thailand.
authors.forename: Anurat
authors.initials: A
authors.lastname: Wisitsoraat
authors.affiliation: National Electronics and Computer Technology Center, Pathumthani 12120, Thailand.
authors.forename: Adisorn
authors.initials: A
authors.lastname: Tuantranont
authors.affiliation: Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
authors.forename: Sukon
authors.initials: S
authors.lastname: Phanichphant
keywords: Au-loaded ZnO; Composite films; Flame spray pyrolysis; NH3 sensor; P3HT