Absorption spectra of Se8-ring clusters in zeolite 5A

Samples with different weight ratio of Se to zeolite 5A (Se concentration) have been prepared by loading Se into the pores of zeolite 5A, and the measuerments of the absorption and Raman spectra have been carried out for the prepared samples. The measured absorption edges of the samples are close to the value for monoclinic Se containing Se8-ring, suggesting the formation of Se8-ring clusters1Se8-ring clusters include single Se8-ring clusters and double Se8-ring clusters. he pores. The continuous and broadening features of the absorption spectra are interpreted by the strong electron-nucleus coupling in the Se8-ring cluster. The absorption edges are red shifted with the increase of the Se concentration. It is tentatively attributed to two reasons. One is the existence of the double Se8-ring cluster in the high Se concentration samples, and the other is that for the strong electron–nucleus coupling cluster, the absorption edge of the clusters system will be red shifted with the increase of the cluster concentration in the clusters system. A single broad band at about 262 cm−1 is observed in the Raman spectra, which further supports the formation of Se8-ring clusters.