rGO doped MOFs derived α-Fe2O3 nanomaterials for self-supporting ppb-level NO2 gas sensor

Metal-organic frameworks (MOFs) derived metal oxide semiconductors (MOSs) with hierarchical and hollow porous structures can reduce detection limits and improve response of gas sensor. Hence, we synthesized reduced graphene oxide (rGO) doped nano-octahedral α-Fe2O3 nanomaterials on Indium-Tin Oxide (ITO) conductive glass as self-supporting NO2 gas sensors by using the solvothermal and calcination methods with MIL-88 as sacrificial templates. Compared to pure α-Fe2O3, the response of rGO/α-Fe2O3-3 sensor improved by more than 8 times and the theoretical detection limit 101 ppb. The improvement in gas response can be attributed to the formation of p-n heterostructure between rGO and α-Fe2O3, as well as the rGO providing more active sites for gas adsorption and special nano-octahedral α-Fe2O3. Consequently, this research provides insights for advancing self-supporting high-performance NO2 sensors based on MOFs derived MOSs.