3D rGO/MXene/In2O3 composite aerogel for high performance formaldehyde detection at room temperature

Two-dimensional layered materials are prone to interlayer stacking in gas sensing applications, leading to a reduction in specific surface area, slow gas diffusion, and inadequate response performance at room temperature. To address these issues, this study employed a combined hydrothermal reduction and freeze-drying method to prepare 3D rGO/MXene/In 2 O 3 composite aerogels, and systematically investigated their microstructure, pore structure, surface chemistry, and formaldehyde sensing behaviour at room temperature. The results indicate that this composite material possesses a continuous, interconnected three-dimensional porous network structure and a high specific surface area (282.78 m 2 /g), which effectively exposes active sites and accelerates gas transport. First-principles calculations confirm the presence of significant interfacial electronic interactions between the multiple components. Under room-temperature testing conditions, the aerogel-based sensor demonstrated a rapid response recovery time (6/8 s) and high formaldehyde response sensitivity (50 ppm, 26.9%), providing an experimental foundation and material design reference for the development of novel room-temperature rapid gas sensors.