Room-Temperature Carbon Monoxide Detection Using Decorated CNT/Ag Sheet Gas Sensors

This work presents the development of a carbon nanotube/silver (CNT/Ag) sheet gas sensor designed for rapid and reliable carbon monoxide (CO) monitoring. The sensing platform is based on conductive carbon nanotube sheets functionalized with silver (Ag) nanoparticles to form a hybrid nanostructured network with enhanced surface activity and electrical transport properties. Surface treatment methods were employed to improve nanoparticle dispersion, interfacial adhesion, and charge transfer between the CNT matrix and Ag nanophase. The sensing mechanism relies on changes in the electrical resistance of the CNT/Ag sheet upon exposure to CO gas. Adsorption of CO molecules on the Ag nanoparticle surfaces alters local electron density and modulates charge transport pathways within the interconnected CNT network, producing a measurable electrical response. Sensor performance was evaluated using a four-point probe configuration at room temperature, demonstrating quantitative detection capability without the need for elevated operating temperatures. The CNT/Ag sheet sensor exhibited reasonable sensitivity, fast response and recovery behavior, and stable operation under ambient conditions. The flexible sheet architecture, combined with the intrinsic conductivity of CNTs and catalytic activity of Ag nanoparticles, provides a lightweight and scalable sensing platform suitable for portable environmental monitoring, industrial safety systems, and smart wearable technologies. These results highlight the potential of CNT/Ag hybrid materials as next-generation gas sensors for efficient and low-energy gas detection capability.