Theoretical and experimental investigation into the photocatalytic degradation of hexachlorobenzene by ZnCr layered double hydroxides with different anions

In this paper, we synthesized five different types of ZnCr layered double hydroxides with different anions (F−, Cl−, Br−, I− and NO3−). A thorough determination of the structure, chemical composition and other physical and chemical properties of the synthesized LDHs materials were done by techniques such as XRD, FTIR, BET, ICP-AES and UV–vis. The photocatalytic degradation of hexachlorobenzene reaction showed that different anions have largely influence on the reactivity and selectivity of the LDHs. The structure stability difference of the LDHs was explained and compared based on the difference of the following physical properties such as Mulliken bonding population, hydrogen bonding and density of states, which were calculated based on DFT theory. It was found that the photocatalytic performance of these LDHs was highly related to their structure stability. In addition, the HCB degradation mechanism was also analyzed by combining GC–MS data and the dissociation energy calculation.