Design engineering of MOF-derived ZnO porous nanofibers functionalized with Pt clusters: Significantly improved acetone sensing properties

For high-performance gas sensors to be used in practical applications, high sensitivity and ultrafast response are essential. Herein, metal-organic framework (MOF)-derived Pt@ZnO porous nanofibers (PNFs) were constructed by using Pt@ZIF-8 as an electrospun precursor. This brand-new Pt@ZnO PNFs combined the benefits of the two classes of porous materials (MOFs and PNFs) and therefore exhibited open porous characteristics. This mesh fiber structure also prevented the growth and aggregation of ultra-small Pt clusters of about 2 nm. As a typical case study, the 0.5 mL Pt@ZnO PNFs demonstrated good sensing performances characterized by high acetone re-sponses (12.2-fold improvement @ 20 ppm) and fast response/recovery times (2 s/5 s) in comparison with ZnO nanocubes. The Pt@ZnO PNFs also displayed good stability and selectivity towards acetone. We credited these improved sensing signals to synergic interactions between Pt clusters and ZnO nanoparticles, the catalytic spillover effect of Pt clusters, and unique mesh nanofiber structure with open porous characteristics. This work provides a novel design method to construct MOF-derived ultra-small noble metal cluster modified mesh metal oxide PNFs with high gas-sensing performance.