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

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. [ABSTRACT FROM AUTHOR]