Oriented assembly of monomicelles in beam stream enabling bimodal mesoporous metal oxide nanofibers

The assembly of monomicelles along one-dimension (1D) to construct tubular or fibrous mesostructures is greatly desired but still challenging. Herein, we have demonstrated a facile strategy to synthesize 1D bimodal mesoporous metal oxides (e.g., WO3, WO3/Pd, WO3/PdCu, TiO2, and ZrO2) nanofibers (NFs) through assembling the organic-inorganic composite monomicelles in a beam stream generated via an electrospinning technique. This facile and repeatable methodology relies on the preparation of copolymer@metal-complex monomicelles in an anisotropic solution and oriented assembly of them in the beam stream by the selective evaporation of solvent. WO3 and its derivatives are chosen as the demo, which show a uniform continuous fibrous structure with dual mesopore sizes (∼4.0 and 7.6 nm) and large surface area (∼93.1 m2 g−1). Benefitting from the unique textual structure, gas sensors made by Pd-decorated mesoporous WO3 NFs display outstanding comprehensive sensing performance to ethylbenzene, including a high sensitivity (52.5), an ultralow detection limit (50 ppb), and fast response/recovery kinetics (11/16 s) as well as an outstanding selectivity, which render them promising for rapid environmental monitoring.