Controllable synthesis of starch-modified ZnMgAl-LDHs for adsorption property improvement

摘要

ZnMgAl-LDHs were prepared by co-precipitation method and modified with starch to transform the structure for the adsorption property improvement. Samples were characterized by XRD, BET, SEM and FT-IR. Effect of starch soluble dosage, initial MO concentration and absorbent dosage on adsorption property of samples was studied. LDH samples modified by starch with starch versus Al3+ mole ratio of 0.0625 and calcinated at 450 degrees C for 5 h, exhibited higher crystallinity, higher surface area and more mesopores, which were beneficial to the adsorption process, the adsorption capacity on methyl orange (MO) reached 1555 mg/g. The kinetic data of adsorption were well fitted by the pseudo-second-order kinetic equation, while the isotherm data were well represented by the Langmuir equation. Starch doped method was a valid means to enhance adsorption performance.