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

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 [PW10Mo2O40]5−. The physicochemical 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 [PW10Mo2O40]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 Qmax of MB onto ZnAl–PW10Mo2 is 30.87 mg/g.

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► Heteropoly blue-pillared layered double hydroxide was obtained for the first time.
► It can be used for the removal of cationic dye from aqueous solutions by adsorption.
► It appears in higher cationic dye adsorption capacity than only LDH.
► The sorption data could be well fitted with the second order kinetic model.