Bimetallic organic framework-derived porous Co3O4/Fe2O3 nanosheets for acetone sensing

Abstract

Bimetallic organic frameworks (Bi-MOFs) are increasingly recognized as highly suitable precursors for developing composite gas sensors based on metal oxide semiconductors (MOS). In this work, we synthesized a Co/Fe-bimetallic organic framework (Co/Fe-Bi-MOF) via an ion-exchange strategy, which was subsequently calcined to obtain porous Co3O4/Fe2O3 nanosheet heterostructures. The prepared porous Co3O4/Fe2O3 nanosheet heterojunction sensing material exhibits excellent acetone gas-sensing performance. At 190 °C, the porous Co3O4/Fe2O3 nanosheet heterojunction material demonstrates remarkable sensitivity to 100 ppm acetone, with a response nearly three times higher than that of pure Co3O4, along with fast response and recovery times and a practical detection limit as low as 1 ppm. Furthermore, the porous Co3O4/Fe2O3 nanosheet heterojunction material also displays outstanding performance characteristics, including reversibility, repeatability, long-term stability, selectivity, and exceptional humidity resistance. Based on various characterization data and DFT simulation results, the enhanced acetone sensitivity is primarily attributed to the synergistic effects arising from the heterojunction structure, large specific surface area, and micro-mesoporous framework. This study provides a promising strategy for developing innovative gas sensors derived from Bi-MOFs.