High-dispersed Fe2O3/Fe nanoparticles residing in 3D honeycomb-like N-doped graphitic carbon as high-performance room-temperature NO2 sensor

This work illustrates a simple polymer thermal treatment strategy to develop high-dispersed Fe2O3/Fe nanoparticles residing in honeycomb-like N-doped graphitic carbon (Fe2O3/Fe@N-GC). The as-prepared Fe2O3/Fe@N-GC composites consist of three-dimensional (3D) strutted interconnective graphitic carbon frame, which would not only refrain from restacking and facilitate the charge transfer, but also provide more reaction interface between gas molecules and materials. Benefiting from the synergistic merits of Fe2O3/Fe, N-doping graphitic carbon, high surface area and unique 3D architectures, the optimal Fe2O3/Fe@N-GC presents impressive sensitivity and selectivity for NO2 gas detection at room temperature with the response of 25.48-100 ppm, response time of 2.13 s, recovery time of 11.73 s, detection limit of 10 ppb and as long as 60 days of stability. As a result, the present Fe2O3/Fe@N-GC composite with an easy fabrication method and high sensitivity, selectivity, stabitliy towards NO2 at RT would inspire various designs based on the 3D honeycomb structure for more real applications in gas sensors.