多级结构MOFs纳米纤维用于甲烷存储研究

Highly structured metal-organic framework nanofibers for methane storage

多孔金属有机骨架材料MOFs在气体存储领域具有潜在应用前景,但是其面向实际应用的加工成型仍具有挑战.本文报道了一种基于静电纺丝技术和相转变结合的方法来构筑MOFs纤维,有效实现了Cu-MOF(HKUST-1)在PAN纳米纤维表面的高效负载.该方法首先将Cu(OH)_(2)生长在PAN纳米纤维表面,进一步通过相转变获得HKUST-1.相比之前的文献报道,该HKUST-1纳米纤维表现出更优异的甲烷存储性能,其在3500 kPa和298 K条件下的甲烷存储量达到86 cm^(3)g^(-1).研究表明该纤维使得负载在表面的MOF高度暴露,具有高的比表面和负载量.该工作为MOFs加工成型并用于能源和环境领域提供了新的思路.

Porous materials such as metal-organic frameworks(MOFs)with high theoretical volumetric gas uptake capacity are promising materials for gas storage and separation,but the structuring for practical applications is challenging.Herein,we report a general and feasible strategy to combine electrospinning with a phase conversion method to decorate polyacrylonitrile nanofibers(PAN NFs)with CuMOF(HKUST-1).The strategy is based on the combination of surface pretreatment of the NFs with Cu(OH)_(2) and a subsequent phase conversion into HKUST-1 crystals(PCHKUST-1).A significant higher loading of HKUST-1 in the PAN NF matrix was achieved by the phase conversion method compared with direct electrospinning of MOF slurries or insitu growth of MOF crystals on NFs.As a result,the hierarchical structured PC(phase conversion)-HKUST-1 NFs revealed the highest gravimetric storage capacity of 86 cm^(3) g^(-1)(STP)at 3500 kPa and 298 K for methane(CH_(4)),which is higher than other HKUST-1 NFs reported previously.The improved CH_(4) uptake can be explained by the high loading of HKUST-1 due to the high availability of Cu-ions localized on the surface of the NFs during the phase conversion process,resulting in high surface area and excellent gas access of the phase converted HKUST-1.Thus,the developed strategy of structuring MOFs could be of interest for the fabrication of tailor-made MOF NF architectures for other energy and environmental applications.