THE INFLUENCE OF AMBIENT TEMPERATURE ON THE THERMODYNAMIC INTERACTIONS GOVERNING AMMONIA ADSORPTION ON THE SURFACE OF PLATINUM NANOPARTICLES/INDIUM GALLIUM OXIDE SENSOR

Abstract

A sensor for detecting ammonia (NH3) has been developed by integrating indium gallium oxide (IGO) thin films with platinum (Pt) nanoparticles. The IGO thin films were fabricated using the radio frequency magnetron sputtering technique, while the Pt nanoparticles were deposited through a thermal evaporation process under vacuum conditions. The incorporation of Pt nanoparticles dramatically improved the sensing performance toward NH3. Extensive characterization of the sensor was conducted to analyze its structural properties, elemental composition, and material characteristics. Experimental results demonstrated that the Pt nanoparticle-decorated IGO sensor achieved a remarkable sensitivity ratio (S-R) of 209.4, when exposed to 1000ppm NH3 in air at an operating temperature of 300 degrees C. The sensor demonstrates outstanding selectivity toward NH3 and exhibits stability under the humidity condition. Notably, even when exposed to a low concentration of 1ppm NH3 in air, the sensor still demonstrated a notable sensitivity ratio of 1.29. To realize the sensing mechanism, an investigation into the adsorption of NH3 molecules on the surface of sensor was implemented.