Great enhancement of CH4 sensitivity of SnO2 based nanofibers by heterogeneous sensitization and catalytic effect

In this study, unloaded and Pt-loaded SnO 2 nanofibers (NFs) with 100–150   nm diameters were synthesized by a simple electrospinning technology and then calcined at 600   °C in air. It was observed that the Pt-SnO 2 NFs were comprised of strings of tiny SnO 2 nanoparticles decorated with Pt and PtO nanoparticles, resulting in the formation of PtO/SnO 2 heterojunction and high porosity. And then, we studied the methane (CH 4 ) sensing performance of the sensors fabricated from these NFs and found that 20   mol% Pt-SnO 2 NFs exhibited excellent CH 4 sensing properties over a temperature range of 100–350   °C, for example, the 20   mol% Pt-SnO 2 NFs showed an obvious response of 1.11–1   ppm CH 4 at 350   °C, which was 2 orders of magnitude lower than the minimum detection limit of the current SnO 2 based CH 4 sensors. The great enhancement of the CH 4 sensing properties of Pt-SnO 2 NFs can be understood by the PtO/SnO 2 heterogeneous sensitization and Pt catalytic effect. Our findings present a novel strategy for the application of SnO 2 based NFs in highly effective CH 4 detection.