Highly stable hydrogen sensing properties of the ZnO/Pt nanoisland deposited on alumina substrate for high temperature operated industrial applications

Abstract

In this work, the Pt decorated ZnO nanoparticles layers are deposited on alumina substrate using the magnetron sputtering method (RF sputtering) and then analyzed with rapid detection of hydrogen gas for an extremely stable hydrogen detecting characteristics. AFM, XRD, and contact angle analysis were utilized to examine the impacts of the rapid thermal annealing (RTA) process at high temperatures. In comparison to the as-grown ZnO film, the XRD spectra of the samples after RTA treatment shows a significant improvement in the amplitude and a shrinking of the (002) diffraction peak's full width at half-maximum (FWHM). FE-SEM and XPS were used to characterize samples to determine the best material structure for stable sensing performance. In terms of higher operating temperature (300°C), stronger selectivity, and long-term durability are obtained from the ZnO-Pt system, which exhibited the best dynamic and transient gas sensing behaviors. The optimum sensor had a detection range of 100-1000 ppm, with response rates of 4.2 percent and 14.9 percent for 100 and 1000 ppm, respectively. More importantly, the sensor shows highly stable base resistance (~132.5Ω) and sensing response (~14.9%) for a long-term period of the test. Sensitivity to 1000 ppm NO, CH4, CO, C3H8, and O2 gas was only -0.2%, -0.16%, 0.6%, 0.15%, and 0.4% respectively, showing excellent selectivity. In conclusion, the obtained ZnO/Pt nanoparticles layers on alumina substrate are indeed a worthy material for building high temperature working environments where high-performance H2 gas sensors are needed.