Heteropoly blue-intercalated layered double hydroxides for cationic dye removal from aqueous media

摘要

Heteropoly blue-intercalated layered double hydroxide (HB-LDH) was obtained by aqueous ion exchange of a Zn-Al LDH precursor in nitrate form with the reduced polyoxometalate anions [PW_(10)Mo_2O_(40)]~(5-). The phys-icochemical properties of the product were characterized by the methods of powder X-ray diffraction, infrared spectroscopy, and cyclic voltammetry. The HB-LDH has been used for the removal of cationic dye methylene blue (MB) from aqueous solutions via adsorption. The intercalation of large cluster anion [PW_(10)Mo_2O_4o]~(5-) into LDH could induce the adsorption to cationic dye of MB, obviously. The HB-LDH shows much higher cationic dye adsorption capacity than pure LDH and the maximum adsorption capacity Q_(max )of MB onto ZnAl-PW_(10)Mo_2 is 30.87 mg/g.