Zn-Al layered double hydroxide-based nanocomposite functionalized with an octahedral molybdenum cluster exhibiting prominent photoactive and oxidation properties

Abstract

A new layered double hydroxide (LDH)-based nanocomposite functionalized with an octahedral molybdenum atom cluster (MC) exhibiting prominent photoactive and oxidation properties was synthesized. ZnAl LDH and ZnAl LDH intercalated dodecyl sulfate compounds (abbreviated as LDH-1 and LDH-2 respectively) were prepared by the co-precipitation method in an aqueous solution. The MCs were simply introduced into the LDH-2 by an anion exchangeable method in dimethylformamide under ambient conditions. The extension of the basal spacing of the LDH-1 from 0.9 nm to about 5 nm by intercalating dodecyl sulfate and Mo6 cluster was confirmed by several complementary technics. The octahedral structure of the Mo6 cluster was retained on the outer surface between big nanosheets (NSs) and inner surface between the single layers that were confirmed by ultraviolet-visible absorption and photoluminescence experiments. The possible chemical bonding between the [Mo6Cli8Cla6-x-y(H2O)ax(OH)ay]x-2 (x = 0, 1 or 2 and y = 0, 1, 2, 3; x + y = 3) clusters and LDH-2 was suggested on the basis of by X-ray photoelectron spectroscopy. The excellent photoactive and oxidation performance of the Mo6 cluster on the methylene blue degradation in an aqueous solution was determined in the dark, under UV light (λ =370 nm) or with the existence of H2O2. The combination of the LDH-2 with a high absorbability and recyclability and the Mo6 cluster will be a promising candidate as a heterogenized homogeneous catalyst for removing organic pollutants.