Hollow porous carbons (HPCs) are a class of porous materials with advantages of high surface to volume ratio, large interior cavities, low density, and short diffusion length, which are promising in various applications. Direct carbonization of carbon precursors is the simplest and the most cost-effective method to prepare porous carbons, however, it often leads to non-hollow structures. Herein, we demonstrate the preparation of HPCs through a direct carbonization method with a two-step heating process of zeolitic imidazolate framework-8 (ZIF-8) and tetrafluoroterephthalonitrile (TFTPN). During the carbonization, ZIF-8 nanoparticles first react with TFTPN at low temperature to create polymer coatings on the surface, which are then converted into HPCs at elevated temperature. The obtained HPCs show hierarchically porous structure with high specific surface areas and pore volumes. Additionally, this method has been adopted to fabricate Au@HPCs yolk–shell composites, exhibiting good catalytic performance in nitrobenzene reduction. The developed synthesis strategy can enrich the toolbox for the preparation of novel HPCs and their composites.

Metal-organic framework (MOF)/polymer composites have attracted extensive attention in the recent years. However, it still remains challenging to efficiently and effectively fabricate these composite materials. In this study, we propose a facile one-pot electrospinning strategy for preparation of HKUST-1/polyacrylonitrile (PAN) nanofibrous membranes from a homogeneous stock solution containing HKUST-1 precursors and PAN. MOF crystallization and polymer solidification occur simultaneously during the electrospinning process, thus avoiding the issues of aggregation and troublesome multistep fabrication of the conventional approach. The obtained HKUST-1/PAN electrospun membranes show uniform MOF distribution throughout the nanofibers and yield good mechanical properties. The membranes are used as separators in Li-metal full batteries under harsh testing conditions, using an ultrathin Li-metal anode, a high mass loading cathode, and the HKUST-1/PAN nanofibrous separator. The results demonstrate significantly improved cycling performance (capacity retention of 83.1% after 200 cycles) under a low negative to positive capacity ratio (N/P ratio of 1.86). The improvement can be attributed to an enhanced wettability of the separator towards electrolyte stemmed from the nanofibrous structure, and a uniform lithium ion flux stabilized by the open metal sites of uniformly distributed HKUST-1 particles in the membrane during cycling.