Porous Double-Channel Α-Fe2o3/Sno2 Heterostructures with Multiple Electronic Transmission Routes for the Enhanced N,N-Dimethylformamide Gas-Sensing Performance

Abstract

Porous double-channel α-Fe2O3/SnO2 heterostructures with tunable surface/interface transport mechanism have been initially fabricated by the electrospinning and subsequent calcination process. As the introduction of Sn4+ into the precursor solution increasing, the morphologies of α-Fe2O3-based materials are transformed from porous fibers to ribbons with the curl inward on both sides, contributing to form the porous double-channel structure features as the adding amount of Sn component reaching to 3 mol%. It is obvious that the gas-sensing performance of various α-Fe2O3 and α-Fe2O3/SnO2 products under high operating temperature can be strongly dependent on the combination of phase structure, particle configuration, and electron transport process. For example, the optimal α-Fe2O3/SnO2 composites exhibit the highest response value (32.38) and fastest response/recovery times (33/58 s) than those of other samples to 100 ppm N,N-dimethylformamide (DMF) at the operating temperature of 360 °C, along with the superior gas selectivity and cycling stability, mainly ascribed from the formation of α-Fe2O3-SnO2 heterojunctions, the increased specific surface area, and the unique surface/interface multiple electronic transmission routes. Significantly, porous double-channel α-Fe2O3/SnO2 composites are expected to become the potential candidates for DMF vapor detection in dye or pesticide industrial field to prevent the DMF explosion under high temperature condition in the future.

Keywords: Gas sensor, porous, double-channel, α-Fe2O3/SnO2 heterostructures, DMF