High response hydrogen gas sensor based on palladium coated multi-walled carbon nanotube

Abstract

H2, which has a zero-carbon footprint, is expected to be one of the main energy sources in the future. The sensitive detection of H2 in the transportation, storage and energy production processes will allow the active use of this resource. Recently, there are many studies in which nanotube-shaped structures are used as high-response gas sensors. In this study, H2 gas response parameters at different temperatures (150, 200 and 250 ºC) of multi-walled carbon nanotube (MWCNT), which were grown on quartz substrate by spin coating method and then Pd coated with DC sputtering, were investigated. The measurements were made at a gas concentration of 1000 ppm with the help of a current-sensitive gas sensor system. The crystallographic structure, elemental content, oxidation levels and surface morphological properties of the produced film were determined by XRS, XPS and SEM analysis. XRD and XPS analyzes support that the MWCNT used in the study is well graphitized and the formation of PdO compound in the structure with Pd coating. The temperature-dependent H2 gas sensing measurements showed that the produced Pd-MWCNT structure had a very high gas response and the highest response was at 200 °C. Comparing the response values obtained with the results of other Pd-CNT structures in the literature, it was determined that the film produced by the economical spin coating method had a very high gas response.