Selective H2S sensing without external heat by a synergy effect in self-heated CuO-functionalized SnO2-ZnO core-shell nanowires

Abstract

Future gas sensors require minimal power consumption to enable their integration into portable electronics such as smart mobile phones. We developed H2S gas sensors based on a self-heating effect using metal oxide nanowires (NWs). We fabricated bare SnO2 NWs, CuO functionalized SnO2 NWs, and a CuO functionalized SnO2-ZnO core-shell (C–S) NW sensor, and tested their sensor response towards H2S gas by applying different external voltages at room temperature. It was found that the CuO functionalized SnO2-ZnO C-S NW gas sensor had higher response to H2S gas relative to other tested sensors due to higher self-heating effect, formation of heterojunctions, phase transformation, and spillover effects of CuO nanoparticles. Without external heat, the selective H2S detection obtained in this work demonstrates the possibility of embedding low power consumption gas sensors in portable devices for detection of H2S as a biomarker for early diagnosis of diseases.