Preparation, channel surface hydroxyl characterization and photoluminescence properties of nanoporous nickel phosphate VSB-1

VSB-1 is one of the most important thermostable nanoporous transition metal phosphates. The synthetic condition was discussed in detail. Hydroxyl groups on the channel surface of VSB-1 play a critical role in the reactions requiring Bronsted acidity. The types of hydroxyl groups of VSB-1 material were distinguished by in situ FT-IR measurements for the samples before and after silylation. In addition, ion exchange studies showed that the hydroxyl groups in VSB-1 were acidic. The acidic site density and acid strength of VSB-1 were measured by NH3-TPD. Violet-blue photoluminescence (PL) emission bands at 412, 436 and 470 nm were observed for VSB-1 at ambient temperature. Enhanced PL intensities were obtained by encapsulating CuO, NiO and CoO nanoclusters in the channels of VSB-1.