Enhanced Gas Sensing Performance of Heterostructure Sensors Based on H-NCD, MoS₂, and Functionalized Graphene Oxide for Ethanol, NH₃, and NO₂ Detection

Abstract

This study investigates the gas-sensing capabilities of heterostructure sensors based on hydrogen-terminated nanocrystalline diamond (H-NCD), molybdenum disulfide (MoS₂), and functionalized graphene oxide (SH-GO, GO) for detecting ethanol, ammonia (NH₃), and nitrogen dioxide (NO₂) gases at 100 ppm concentrations. Sensors were tested at two distinct temperatures: 125°C and room temperature (22°C). Among the tested sensors, the SH-GO/H-NCD exhibited the highest sensitivity to ethanol, with a response of 634% at 22°C and 554% at 125°C. The Au NPs/H-NCD sensor showed the second-best ethanol response of 587% at 125°C. For NH₃, SH-GO/H-NCD demonstrated the best response at 125°C with a value of 76%, while at room temperature, it showed 41%. NO₂ sensing showed negative responses, with the SH-GO/H-NCD sensor exhibiting the least degradation at -47% at 125°C and -19% at 22°C. The results highlight those combining materials into heterostructures significantly enhances gas detection performance, even at room temperature, showing comparable responses to commercial sensors.

Keywords

• h-ncd
• mos₂
• sh-go
• gas sensors
• heterostructures
• ethanol detection
• ammonia detection
• nitrogen dioxide detection