High-Temperature resistant ethanol sensing enhanced by ZnO Nanoparticles/SiC nanowire heterojunctions

Abstract

Metal-oxide (MO) semiconductors are important materials for developing sensors to detect toxic gases and chemicals. However, achieving robust thermal and chemical stability under harsh working conditions, such as high temperatures, remains a significant challenge. Here, we present the construction of a high-temperature resistant ethanol sensor based on rationally designed heterojunctions formed by ZnO nanoparticles and β-SiC single-crystalline nanowires (ZnO-NPs/β-SiC-NWs). The formation of ZnO-NPs/β-SiC-NWs heterojunctions is achieved through a simple hydrothermal process, allowing the anchoring of ZnO NPs on the surface of SiC NWs. As a result, the assembled sensor demonstrates significantly improved performance in sensing ethanol at 465 °C. It exhibits a high response (S = 25.4 at 100 ppm), compared to pure ZnO NPs (10.4) and β-SiC NWs (1.2), along with fast detection (response/recovery time = 19/49 s), excellent selectivity, and a detection limit down to ppb levels. The archived response value surpasses the previously reported MO-based analogues at the similar temperatures and suggests promising applications for stable sensors operating under harsh working conditions.