Engineering 2D In2O3/SnO2 heterointerfaces via van der Waals stripping for enhanced ethanol sensing performance and mechanism insight

Two-dimensional (2D) graphene-like metal oxides are promising for gas sensing due to their high surface area to volume ratio. This study presents an optimized van der Waals stripping method for fabricating ultrathin In 2 O 3 and SnO 2 films and the In 2 O 3 / SnO 2 heterostructure. The heterojunction sensor demonstrated high performance ethanol detection at 100 ppm, with a response value (R a /R g ) of 13.93, rapid response/recovery times (7 s/29 s), and excellent selectivity. Density functional theory (DFT) simulations revealed that the enhanced performance originates from synergistic interfacial effects that promote electron transfer and selective ethanol adsorption. This work provides a scalable strategy for synthesizing 2D heterostructures and demonstrates their potential for developing advanced gas sensors.