MoS2 nanosheets-decorated SnO2 nanofibers for enhanced SO2 gas sensing performance and classification of CO, NH3 and H2 gases

Abstract

The effect of MoS₂ nanosheet (NS) decoration on the gas-sensing properties of SnO₂ nanofibers (NFs) was investigated. The decorated sensors were fabricated by facile on-chip electrospinning technique and subsequently dropping MoS₂ NSs-dispersed solution. The MoS₂ NS decoration resulted in enhanced the response and reduced the operating temperature of SnO₂ NFs towards SO₂ gas. The SnO₂ NF sensor decorated with the optimum density of MoS₂ NSs exhibited about 10-fold enhancement in gas response to 10 ppm SO₂ at 150 °C as compared with the bare SnO₂ NF sensor. Furthermore, the decorated sensors exhibited an extremely low detection limit and good selectivity for SO₂ gas against other interfering gases, such as CO, NH₃, and H₂. The enhanced SO₂ gas-sensing performance of MoS₂ NSs-decorated SnO₂ NFs was attributed to the chemical sensitization of MoS₂ NSs and charge transfer through heterojunctions between the NSs and SnO₂ nanograins. The classification of toxic gases such as CO, H_2, and NH₃ by the MoS₂ NSs-decorated SnO₂ NF sensors can achieve high accuracy with linear discriminant analysis (LDA). Our results suggest that the one-dimensional nanostructures of semiconductor metal oxides decorated with two-dimensional transition metal dichalcogenides are attractive candidates for the detection of hazardous gases.

Keywords: Electrospinning; Gas sensors; MoS(2); Nanofibers; SO(2); SnO(2).