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

束流中的胶束定向组装制备双介孔金属氧化物纳米纤维

The assembly of monomicelles along onedimension(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.,WO_(3),WO_(3)/Pd,WO_(3)/Pd Cu,TiO_(2),and ZrO_(2))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.WO_(3)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 m^(2)g^(-1)).Benefitting from the unique textual structure,gas sensors made by Pd-decorated mesoporous WO_(3)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.

利用胶束的一维(1D)定向组装来构建管状或纤维状的介孔材料具有重要的科学意义,但仍面临巨大挑战.本文中,我们提出了一种简单、普适的合成策略,通过静电纺丝产生的束流限域有机-无机复合胶束使其沿着1D方向组装,从而构建一系列双介孔金属氧化物纳米纤维(如WO_(3),WO_(3)/Pd,WO_(3)/Pd Cu,TiO_(2)和ZrO_(2)).这种方法主要依赖于共聚物@金属络合物复合胶束在各向异性溶液中的形成,然后通过溶剂的选择诱导使它们在束流中定向组装.以WO_(3)及其衍生物为例,所得到WO_(3)纤维显示出均一的连续纤维结构,具有双介孔尺寸(~4.0和7.6 n m)和较大的比表面积(~93.1 m^(2)g^(-1)).将钯修饰的介孔WO_(3)纳米纤维用于乙苯气体传感器,展现出了优异的综合传感性能,如高灵敏度(52.5)、超低浓度检测限(50 ppb)、快速的响应/恢复动力学(11/16 s)和优异的选择性,在环境快速监测方面显示了广阔的应用前景.