Metal–organic frameworks for visible light absorption via anion substitution

Abstract

We report that the band gap of metal–organic frameworks (MOFs) could be tuned to absorb visible light via anion substitution. First of all, when an oxygen anion in the metal oxide core of IRMOF-1 is substituted with sulphur anions as Zn₄S or selenium anions as Zn₄Se to form IRMOF-1-S and IRMOF-1-Se, respectively, they result in density-of-states and molecular orbitals for the band gap that can utilize visible light through shifting of the Fermi level due to their electron-rich properties. This implies that the tailored band gap could provide a new route to allow the series of IRMOFs and other MOFs to be used for visible light absorption.