Novel high performance room temperature hydrogen sensor - 3D In2O3@rGO@PPy aerogel with dual enhancement of mechanical and gas sensitive properties

A novel three-dimensional In₂O₃-rGO-PPy composite aerogel was synthesized using a hydrothermal method, achieving high sensitivity and selectivity in hydrogen sensing at room temperature. The aerogel was supported by the skeleton of hollow tubular PPy nanotubes, which not only enhanced the mechanical properties of the material but also maintained the excellent electrical conductivity of the material and suppressed the stacking of the rGO layer. Based on the improvement of the mechanical properties of the aerogel, the Holistic Testing Method (HTM) was innovatively developed to avoid damage to the structural integrity of the 3D network caused by the Forked Finger Electrode Method (FEM). Without adding precious metals and at room temperature, the In4-rGO-PPy₂-H sample showed a response as high as 11.6–1000 ppm H₂, with a response/recovery time (t_res/t_rec) as low as 13/29 s. In addition, the sensor exhibits excellent selectivity and humidity resistance. These excellent properties indicate that In4-rGO-PPy₂ has improved response values and speed and has a promising application.