Heterojunction of Pores in Granola-Type Crystals of Two Different Metal-Organic Frameworks for Enhanced Formaldehyde Removal

Abstract

Metal-organic frameworks (MOFs) have introduced heterogeneity in their homogeneous matrix to create new functions that cannot be realized by each MOF individually. In this study, we chemically combined two different MOFs (UiO-66 and HKUST-1) in granola-type granules (termed as HKUST-1 perpendicular to UiO-66) to create a heterojunction of pores in nanocrystalline particles. The structure, morphology, elemental composition, and pore environment were characterized to confirm that two types of pores are in conjunction all over the HKUST-1 perpendicular to UiO-66 granules. We found that the HKUST-1 perpendicular to UiO-66 granules showed an enhanced CO2 sorption capacity than its constituents due to the complexity and the heterojunction of pores inside. Moreover, the HKUST-1 perpendicular to UiO-66 granules present four and two times higher formaldehyde removal capacity than those of the HKUST-1 and UiO-66 samples, respectively.