Controllable synthesis of an intercalated SnS2/aEG structure for enhanced NO2 gas sensing performance at room temperature

Abstract

Intercalated SnS₂/actived expanded graphite (SnS₂/aEG) nanocomposites (NCs) were prepared via a vacuum-assisted and facile solvothermal technique. It suggests that SnS₂ nanoflowers (NFs) evenly distribute on the surface and interlayer of aEG nanosheets (NSs) by regulating the ratio of SnS₂ and aEG. Compared with the gas sensitivity of pure SnS₂ and pure aEG at 100 ppm NO₂, the SnS₂/aEG-III sensor device exhibits superior performance with a short response (0.53 s) and recovery (51.73 s), prominent selectivity, endurance stability and an enhanced response (21.19) at room temperature (RT). The detection limit can reach 10 ppb and the response value is 1.04. The improved NO₂ sensing performance is attributed to the synergistic effects of SnS₂ NFs and aEG NSs, simultaneously along with the p–n heterojunctions/defects, which facilitate electron transfer and provide more active sites for NO₂ gas. This study demonstrates the great potential of SnS₂/aEG-III in the application of semiconductor NO₂ sensors.