Optical and structural studies of CuI clusters in zeolites LTA and FAU

Abstract

CuI clusters were incorporated into α-cages and supercages of zeolites LTA and FAU, respectively, with various loading densities. From the powder XRD measurement of CuI clusters in FAU, it can be concluded that CuI clusters with homogeneous size were distributed in the cages. In case of using FAU as a host, when the loading density became close to the maximum, photo absorption intensity gradually decreased. A polariton effect, i.e. photo excited energy transfers among the clusters, may play an important role on this phenomenon. Cu and I atoms of bulk CuI crystal have tetrahedral chemical bondings. Supercages of FAU have an arrangement of a diamond structure. Coincidence on the symmetry of the chemical bondings in the CuI clusters and the arrangement of the clusters in the supercages may be the origin of a highly ordered state of CuI clusters and will enhance the polariton effect.