1D hollow In2O3@ZnFe2O4 core-shell heterostructure for enhanced ppb-level acetone detection

Sensitive and selective acetone detection is critical for environmental monitoring and disease diagnostics, yet current sensors suffer from high operating temperatures and insufficient sensitivity. This study innovatively proposes an electrostatic self-assembly strategy to uniformly anchor small ZnFe 2 O 4 nanoparticles (around 20 nm) onto MOFs-derived one-dimensional (1D) hollow In 2 O 3 nanotubes, leading to the successful construction of an In 2 O 3 @ZnFe 2 O 4 core-shell heterostructure. The sensor based on In 2 O 3 @ZnFe 2 O 4 -7.5 exhibits a high response of 278 towards 200 ppm acetone at 200 °C, a low detection limit of 50 ppb with response of 1.85, good stability and moisture resistance. It is believed that the excellent sensing performance mainly originated in the formation of n-n heterojunction interfaces to enhance interfacial charge transfer and the effective suppression of ZnFe 2 O 4 aggregation. Thus, this work provides a facile strategy for the fabrication of heterojunction for gas sensors.