Photocatalytic O2 evolution from water over Zn–Cr layered double hydroxides intercalated with inorganic anions

Zn–Cr layered double hydroxides (LDHs) intercalated with inorganic anions ( CO 3 2 − , Cl−, SO 4 2 − and NO 3 − ) were synthesized by the co-precipitation method and the anion exchange process. The photocatalytic activity of the LDHs was studied by O2 evolution from aqueous solution of AgNO3 as a sacrificial agent. All the prepared LDHs showed photocatalytic activity under either UV and/or visible light irradiation. Besides, the interlayer anions affected the photocatalytic activity of the LDHs. After irradiation, Ag particles were formed on the LDHs by accepting the electrons generated during the photocatalytic reaction.