Raman studies on the specific adsorption of BPE with PbI2

Intercalation, the insertion of guest atomic and molecular entities into the architecture of a crystal, is an efficient route for generating new materials with novel properties. However, the detailed analysis of their new structure and properties is of great importance, which are still insufficient. Here, 1,2-bis(4-pyridyl)ethylene (BPE) intercalated PbI 2 (BIP) has been investigated by Raman spectroscopy together with correlated studies of scanning electron microscope (SEM), X-ray diffraction (XRD), ultraviolet–visible (UV–Vis) absorption spectrum, and energy-dispersive X-ray spectroscopy (EDS). The Raman spectrum of intercalated compound discloses new lines at 83, 222, and 234 cm −1 with remarkable displacement of the bands at 1001, 1200, 1603, and 1640 cm −1 , indicating a formation of a new crystal and the chemical interaction between the nitrogen atom of guest molecules with PbI 2 host material. XRD confirmed the intercalation of guest molecules into a host matrix through the appearance of diffraction lines at lower angles that are corresponding to the enlarged unit cell in c axis. Furthermore, we also found that the PbI 2 can specifically adsorb of BPE molecules, which was confirmed by an adsorption experiment revealed by adsorption capacity toward BPE is higher than 2,2-bipyridine and 4,4-bipyridine, suggesting the good adsorptive selectivity toward BPE by PbI 2 film. This work further demonstrated our mechanism on enhanced Raman spectroscopy on PbI 2 . It is believed that this unusual discovery not only enables PbI 2 to be a specific adsorbent, which also provides a new advance toward a better understanding of structure about PbI 2 .