Preparation and characterization of layered-double hydroxides decorated on graphene oxide for dye removal from aqueous solution

Abstract

In this study, coprecipitation method followed by sonochemical treatment was used to prepare layered-double hydroxides (LDH) and graphene oxide-layered-double hydroxides (GO-LDH). GO-LDH and LDH adsorption performance were evaluated using aqueous solution of Methyl Orange dye (MO). The LDH and GO-LDH were characterized using various advanced techniques. The analysis of data collected from the XRD pattern and size distribution showed that the presence of GO will increase the inter-space between the LDH layers and the polydispersity index than pure LDH. This will make the ion exchange be easier and improve the adsorption process. The adsorption kinetic studies presented that the adsorption of MO dye on LDH and GO-LDH follows a pseudo-second-order reaction. Moreover, according to intraparticle diffusion, GO-LDH has a faster diffusion constant for MO molecules than LDH. Furthermore, as predicted by Langmuir, the maximum adsorption ability of MO using GO-LDH (505.1 mgg−1) which was higher than LDH (400 mgg−1). Finally, LDH and GO-LDH were successfully regenerated using 1.0 M NaOH and Methanol, respectively. Moreover, the GO-LDH showed excellent reusability behavior compared to LDH. This suggests that GO-LDH could be a costless adsorbent compared to LDH.

Keywords

• LDH
• GO-LDH
• Anionic dye
• Adsorption
• Recycling