Core–shell SnO₂/NiO p–n heterojunction composite for enhanced triethylamine gas sensitivity and selectivity

This study explores the development of a gas sensor based on SnO₂/NiO heterostructures for detecting volatile organic compounds (VOCs), notably triethylamine (TEA). The sensor's operational principles, including TEA molecule interaction with adsorbed oxygen and electron transfer mechanisms affecting sensor resistance, are thoroughly analyzed. SnO₂/NiO core–shell heterojunction nanowires were synthesized via a vapor–liquid–solid (VLS) and hydrothermal process. Characterization techniques such as field-emission-scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), field-emission transmission electron microscopy (FE-TEM) with energy-dispersive X-ray spectroscopy (EDS), and nitrogen gas adsorption (BET method) were employed. Experimental results demonstrate exceptional sensor performance at 300 °C, showing rapid response and recovery to TEA with high stability over extended use. This research highlights the promise of SnO₂/NiO heterostructures for advanced gas-sensing applications, surpassing conventional sensor technologies.