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