Noticeable improvement in adsorption capacity of glycine-modified MgAl-LDH in the removal of Methyl Orange dye compared to urea standard method

ABSTRACT In this paper, a simple chemical method in the presence of glycine is described to fabricate the hierarchical structure of MgAl-based Layered Double Hydroxides (Gly-LDH), served as high-performance adsorbent for Methyl orange (MO) . To elucidate the effect of glycine on the adsorption capacity, the MgAl-LDH intercalated with CO3 2- anions was also prepared by urea hydrolysis method (Ur-LDH). The as-synthesised nanostructures were characterised by X-ray diffraction (XRD), Thermogravimetry/Differential Scanning Calorimetry (TG–DSC), Fourier transform infrared spectroscopy (FTIR), and Scanning Electron Microscopy (SEM), . The results demonstrated that the glycine intercalated LDH exhibited high adsorption capacity for MO dye compared with MgAl-LDH obtained by urea hydrolysis method. Adsorption isotherm data for MO adsorption on Gly-LDH at 300 K and acidic pH fitted well to the Langmuir isotherm model with a maximum adsorption capacity of 800 mg/g. l. The sorption mechanism indicates that MO molecules could be sorbed onto Gly-LDH via electrostatic attraction, and ion exchange.