Reduced graphene oxide spatially scaffolded by a sucrose-derived carbon framework for trace and fast gas detection

3D graphene is a promising candidate in high-performance gas sensing due to its unique porous structures. However, proper construction and finely regulation of the architecture for trace and fast detection of various gases is still challenging. Here, we propose a novel combustion approach to the construction of 3D reduced graphene oxide (RGO), which is incorporated in a sucrose-derived carbon framework, stretched out and spatially scaffolded by the skeleton. The composite foam was quickly bubbled from the mixture of sucrose, graphene oxide (GO) and sodium carbonate within a flame of ethanol. Sodium carbonate acts as a catalyst accelerating pyrolysis. The thickness of the RGO-based walls can be down to mono-layers. Toward detecting nitrogen dioxide (NO2), the limit of detection (LOD) of the rinsed foam is 17.8 ppb, which can be down to 0.7 ppb after a heat-treatment at 600 °C. The response time is also decreased to 100 s when measured toward 5 ppm NO2. This work not only demonstrates a simple and fast method to the building of 3D graphene, but also presents a promising candidate for the trace and fast detection of NO2 with high sensitivity and good selectivity.