Construction of novel Heat-conducting Cu-based MOF nanocomposite (HK-mBNNS/PVDF) film for highly efficient Ad-/desorption of toluene

Metal-organic frameworks (MOFs) modification and composite to chase high adsorption capacity and desorption efficiency for volatile organic compounds (VOCs) capture are a great challenge work. Seeking a suitable strategy to simultaneously promote the adsorption capacity and regeneration efficiency of MOFs is a significant practical challenge in this context. Herein, novel heat-conducting MOFs (HKUST-1) composite films were prepared for efficient and synchronous improvement of adsorption affinity and desorption efficiency. In our case, bulk Boron nitride (BN) was exfoliated into BN nano-sheets (BNNS), which were then spread as flakes on PVDF nanofibers to form a conductive network (BNNS/PVDF film, which was abbreviated as B/P film). With the aid of citric acid (CA) modification, HKUST-1 crystals were dispersed-grown on modified B/P (mB/P) film, resulting in the formation of a hierarchical pore structure in HK-mB/P film with a relatively high MOFs loading amount (45.8 wt%) and surface area (448 m2/g). Performance evaluation experiments showed that the toluene adsorption and desorption rates of the HK-mB0.4/P0.6 film were 5.5 and 5.3 times higher than those of the powder HKUST-1, respectively. The fast adsorption rate could be ascribed to the constructed heat-conducting network and porous stacked nanofibers. Furthermore, its adsorption capacity for toluene was significantly increased up to 4.69 mmol/g at low pressure (P/P0 = 0.01), which was approximately-two times higher than that of pure HKUST-1. This merit was mainly attributed to the newly formed interface between HKUST-1 and mBNNS, which could strengthen the adsorption affinity for toluene by the generated unsaturated metal sites of (BNNS-CA-O|Cu|O-ligand) and π-π attraction of B-N bonds. Besides, the HK-mB0.4/P0.6 film also displayed good cycling performance, with only a 3–4 % decrease in activity observed after five consecutive cycles.