A simple computational model for MOF-5W absorption and photoluminescence to distinguish MOF-5 from its hydrolysis products

Abstract

In the present study, changes in absorptance and emission spectra of MOF-5 after being exposed to water are examined in detail and compared with DFT calculations. The results of the computational studies show the effect of water molecules in the absorptance spectra of MOF-5W, the first hydrolysis product of MOF-5, highlighting the role of the protonation of the ligand on the bandgap of these materials. Finally, the photoluminescence of MOF-5, MOF-5W and MOF-5H (the final hydrolysis product of MOF-5) is analysed in detail. These results indicate that changes in MOF-5 framework caused by the presence of water can be simply tracked by luminescence spectroscopy, making it possible to analyse the degree of hydrolysis (whether the sample contains MOF-5, MOF-5W or MOF-5H) without resorting to XRD analysis, for example.