Facile synthesis of rose-like composites of zeolites and layered double hydroxides: Growth mechanism and enhanced properties.

Excellent performances of various materials often depend on high specific surface areas. Therefore, increase of specific surface areas is one of the most important means to improve the properties and performances of materials. Herein, we report a facile strategy to prepare novel composite materials of zeolites and hydrotalcite-like layered double hydroxides, with high specific surface areas. The composites with a rose-like morphology were synthesized hydrothermally by adding synthetic zeolites to the raw materials used for the formation of hydrotalcite. The resultant composites were shown to contain two distinct layered double hydroxides with different Mg/Al molar ratios. Nitrogen (N) adsorption-desorption measurements showed that the specific surface areas and the pore volumes of these composites increased by an order of magnitude in comparison with hydrotalcite. The new composites were shown to be capable of effectively removing Cr(VI), Cu(II) and methylene blue from aqueous environments and had better performances for the latter two contaminants than hydrotalcite. Moreover, this strategy potentially opens up the synthesis of new composite materials with tunable compositions and enhanced properties for environmental and other applications.