Pt@NiO core–shell nanostructure for a hydrogen gas sensor

Abstract

In this study, a novel core–shell Pt@NiO-based hydrogen gas sensor was investigated. Core–shell Pt@NiO was prepared through the sol-gel method, and the sensor device was fabricated by coating core–shell Pt@NiO on an alumina substrate. The structure and morphology of core–shell Pt@NiO was examined using X-ray diffraction, transmission electron microscopy, and energy-dispersive spectrometry. The sensing properties of NiO, Pt/NiO, and core–shell Pt@NiO were investigated, and Pt@NiO (4.25) was observed to have a higher response than Pt/NiO (1.25) and NiO (1.02) to 5000 ppm H2. The sensor response was 4.25–5000 ppm H2 on Pt@NiO at room temperature with a short recovery time (Tr90 = 8 s). Excellent linearity (R2 = 0.9976) from 1000 to 7000 ppm H2 and high selectivity of the sensing material was observed. Thus, core–shell Pt@NiO exhibits considerable potential to be developed as a selective hydrogen sensor.