Hybridization of layered zirconium phosphate with azo compounds and its photoresponsivity and adsorption of rare earth elements

Intercalation treatments of azo compounds were performed in the interlayer space of alpha- and gamma-zirconium phosphates (ZrP). X-ray diffraction patterns confirmed that the intercalation of the azo compounds into alpha-ZrP occurred via an octylamine intercalated intermediate. CHN elemental analysis indicated that the azo compounds were substituted for pre-intercalated octylamine. In contrast, all azo compounds tested except for p-hydroxyazobenzene were directly intercalated into the interlayer space of gamma-ZrP without octylamine. Photoisomerization of p-aminoazobenzene and p-hydroxyazobenzene included in gamma-ZrP was observed along with their reversibility, as determined by alternate ultraviolet and visible photoirradiation for 30 min. The adsorption competency of the prepared materials for rare earth cation significantly increased depending on the azo molecule density. (C) 2019 The Ceramic Society of Japan. All rights reserved.