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.