Nanoparticle@Metal-Organic Frameworks as a Template for Hierarchical Porous Carbon Sponges

The preparation of hierarchical porous carbon sponges (HCS) from metal oxide nanoparticle@metal-organic frameworks is reported. ZnO nanoparticles are partially converted to zeolitic imidazolate framework-8 (ZIF-8) crystals in presence of n-butylamine to obtain ZnO@ZIF-8 porous hybrids. After direct carbonization, followed by ZnO acidic etching, ZnO@ZIF-8 crystals were converted to submicrometric HCS. Due to the high surface area and accessible porosity, combining micro- and mesoporosity of HCS, their application for the extraction of water pollutants was studied by preparing HCS/polymer membranes, and showed a high efficiency for the fast (650 L m^-2  h^-1 ) removal of plastic degradation by-products (DBP, dibutyl phthalate. DEHP, bis(2-n-ethylhexyl)phthalate). DBP and DEHP breakthroughs were lower than 3 % after the filtration of 100 mL of water containing simultaneously both phthalates at a high concentration level (300 μg L^-1 , each). HCS/polymer membranes were reusable up to 5 times, maintaining their extraction capacity, with relative errors of 6 % for DBP, and <1 % for DEHP.