Mixed-linker strategy for superior 1D MOF-derived p-n junction acetone sensors

Controlling the morphology of metal–organic frameworks (MOFs) is critical for tailoring their transformation into metal oxides with unique microstructures and properties, particularly for gas sensing applications. In this study, a dual In-MOF-MF was developed using a mixed linker approach involving terephthalic acid and fumaric acid. These two linkers interact with In^{3 +} ions to produce nanofibers with a high aspect ratio. The resulting In₂O₃-MF exhibits superior acetone sensing properties compared to In₂O₃ derived from single-linker MOFs. Furthermore, the n-type In₂O₃-MF was coupled with p-type PtO to create a p-n junction gas sensor. The combination of rich active sites and the well-defined coupling interfaces between PtO and In₂O₃-MF leads to remarkable acetone sensing performance, featuring a high response (347–100 ppm acetone), rapid response/recovery time (34/18 s), excellent selectivity, and a relatively low detection limit (300 ppb). This work highlights a mixed-linker strategy for MOF morphology manipulation, enabling the fabrication of a one-dimensional p-n junction for next-generation advanced acetone sensing applications.