Insights into the role of metal cation substitution on the anionic dye removal performance of CoAl-LDH

The preparation of the adsorbent plays an important role in the adsorption technology, especially the selection of adsorbents with high specific surface area and special structure is particularly critical to the entire adsorption process. Herein, a series of ternary LDHs was designed via a facile hydrothermal method, and in another word, all derived from binary CoAl-LDH by substituting with another transition metals(Ni, Zn, Fe), used as adsorbents to remove MO and CR. The adsorption capacity of the obtained ternary LDHs are better than that of the pristine CoAl-LDH, and CoNiAl-LDH stands out with the higher adsorption capacity than other ternary LDHs samples whether the dye is MO or CR. Then the effect of initial dye concentration, pH and temperature on its MO adsorption performance was systematically studied. The maximum adsorption capacity reached more than 330 mg/g under the optimal conditions (25 degrees C, pH=3). This work may provide a method to design the advanced adsorbents design for further enhancing the adsorption activity in the field of water environmental protection.

Automated summary

A series of ternary LDHs were designed as adsorbents to remove MO and CR, with CoNiAl-LDH showing higher adsorption capacity than other ternary LDHs samples. The maximum adsorption capacity reached over 330 mg/g under optimal conditions of 25 degrees C and pH=3.