Metal–organic framework-derived mesoporous rGO–ZnO composite nanofibers for enhanced isopropanol sensing properties

Metal–organic framework (MOF)-derived porous reduced graphene oxide (rGO)–ZnO composite nanofibers (NFs) were fabricated by using rGO and zeolitic imidazolate framework-8 (ZIF-8) as electrospun precursors. The prepared materials were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectrum (XPS), ultraviolet photoelectron spectroscopy (UPS), and the Brunauer–Emmet–Teller (BET) method, respectively. This innovative rGO–ZnO composite NFs integrated the advantages of two kinds of porous material (MOFs and NFs), thereby displayed high density and large-size mesopores. Sensing results indicated that the 3 mL rGO–ZnO NFs demonstrated good sensing properties characterized by higher isopropanol (IPA) sensing responses (2.8-fold improvement @ 50 ppm) and faster response/recovery times (14 s/39 s) in comparison with pure ZnO nanocages. In addition, good selectivity and stability towards IPA of the 3 mL rGO–ZnO NFs were also observed. High IPA sensing properties were attributed to the synergic coupling between rGO nanosheets and ZnO nanoparticles, as well as the unique MOF-derived 3D mesh nanofiber structure with large-size mesopores, high surface area, and anti-aggregation property. This study presents a new approach for constructing MOF-derived porous rGO–metal oxide composite mesh NFs sensing materials with high-performances.