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

¹ Peter the Great St. Petersburg Polytechnic University, Saint Petersburg 195251, Russian Federation
² Lovely Professional University, Phagwara, Punjab, India
³ Department of Civil, GRIET, Bachupally, Hyderabad, Telangana, India.
⁴ Department of Electronics & Communication Engineering, KG Reddy College of Engineering and Technology, Chilkur(Vil), Moinabad(M), Ranga Reddy(Dist), Hyderabad, 500075, Telangana, India.
⁵ Uttaranchal University, Dehradun - 248007, India
⁶ Centre of Research Impact and Outcome, Chitkara University, Rajpura - 140417, Punjab, India
⁷ Chitkara Centre for Research and Development, Chitkara University, Himachal Pradesh - 174103 India
⁸ University School of Mechanical Engineering, Research & Incubation Centre, Rayat Bahra University, Chandigarh-Ropar NH 205, Greater Mohali, Punjab, 140103, India

^* Corresponding author: darya0690@mail.ru

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.