Highly stable hydrogen sensing properties of Pt–ZnO nanoparticle layers deposited on an alumina substrate for high-temperature industrial applications

Abstract

Platinum (Pt)-decorated zinc oxide (ZnO) nanoparticle (NP) layers were deposited on an alumina (Al2O3) substrate via a magnetron sputtering method, and the resulting Pt–ZnO NP-based sensor was used to detect hydrogen (H2) gas at a high operating temperature of 300 °C, revealing its extremely stable H2 detection properties. Samples of the sensor were characterized using scanning electron, transmission, and atomic force microscopies; X-ray diffractometry; and X-ray photoelectron spectroscopy to determine the optimal structure that exhibits the best sensing performance, prepared by changing the deposition rate and annealing conditions. At a high working temperature of 300 °C, the sensor exhibits resistance changes in the presence of H2 and perfect reversibility in the absence of H2. The fabricated device exhibits a detection range of 100–40,000 ppm and fast response (recovery) time of 133 (112) s toward 1000 ppm (1 vol%) of H2 at 300 °C, with good selectivity. Moreover, the sensor shows highly stable base resistance (~132.5 Ω) and response towards H2 (~14.9%) over long time periods. Thus, the obtained Pt–ZnO/Al2O3 material shows high potential for use in high-temperature working environments where high-performance H2 gas sensors are required.