ZnO nanowire/NiO foam 3D nanostructures for high-performance ethylene glycol sensing

Abstract

Ethylene glycol is widely used in industrial production but poses potential safety hazards to human life and health. Unfortunately, conventional glycol gas sensors have limitations that impede their effectiveness, such as sluggish response rates, high operational temperatures, and complex preparation procedures. A new approach has been explored to address these challenges. A ZnO nanowire/NiO foam nanostructured sensor was developed specifically for rapid ethylene glycol detection. The NiO/ZnO heterojunction-based gas sensor (NZO-6) has inherent p-type gas-sensitive characteristics. Notably, it delivers a response of 58.98–100 ppm of ethylene glycol at a relatively low operating temperature of 175 ℃. At a relatively low operating temperature of 175 ℃, it exhibits a response of 58.98–100 ppm ethylene glycol, 2.28 times higher than NiO foam, and a fast response/recovery time (4 s/26 s). This improvement is attributed to the porous structure of NiO foam/ZnO nanowires, with a large specific surface area and numerous oxygen vacancies generated during synthesis. Additionally, the catalysis of Ni metal and the formation of p/n heterojunctions further contribute to the improved sensing performance. This research offers a promising solution for developing high-performance ethylene glycol gas sensors with potential environmental monitoring, industrial safety, and public health applications. Further, this synthesis method provides an effective strategy for constructing other NiO-based heterostructure-based gas sensors.