Gold-decorated vertically aligned carbon nanofibers for high-performance room-temperature ethanol sensing

Room-temperature detection of volatile organic compounds (VOCs) is a persistent challenge for low-power sensing applications. This study presents a scalable method for fabricating gas sensors based on vertically aligned carbon nanofibers (VACNFs) decorated with aerosol-printed gold nanoparticles (Au NPs). The Au-functionalized CNFs show ~ 140% improvement in response at 10 ppm ethanol gas, reduced ~ 5-s response time, and enhanced stability with over 95% signal retention. These improvements are attributed to increased surface area, enhanced graphitic disorder, and the catalytic activity of Au NPs. Structural and morphological characterization using TEM, EDX, SEM, and Raman spectroscopy confirms the successful decoration of CNFs with Au. The effects of operating temperature and humidity on sensor performance are also evaluated.