MOF-derived Co3O4/Fe2O3 p-n hollow cubes for improved acetone sensing characteristics

In this work, gas-sensing materials based on Co3O4/Fe2O3 nanocubes were prepared via a MOF hybrid-assisted approach with the aid of ion-exchange. Structural characterizations proved the as-prepared Co3O4/Fe2O3 nanocubes possessed hollow porous structures. The formation mechanisms were also investigated. Gas-sensing measurements revealed that the Co3O4/Fe2O3 nanocubes showed high response (Rg/Ra = 3.27) towards acetone, which was 3.06 times higher than that of Co3O4 nanocubes (Rg/Ra = 1.07). The enhanced sensing mechanism of Co3O4/Fe2O3 nanocubes were also discussed, which could be explained by synergistic effects aroused by the as-formed p-n heterojunctions and hollow porous structures that offered numerous diffusion channels and an additional modulation in resistance. Our studies shed a new light to design p-n naoncomposites by a facile MOF hybrid-assisted method. Moreover, the as-designed Co3O4/Fe2O3 nanocubes have potential application for fabricating high performance acetone sensors.