In-situ functionalization of GO sheets with AlOOH-FeOOH composite nanorods: An eco-friendly nanoadsorbent for removal of toxic arsenate ions from water

Water contaminated with arsenic (As) has become a worldwide problem due to its obligatory toxicity. Therefore, there is a great challenge for researchers to develop a cost-effective and highly efficient nanoadsorbent material for As removal. In this work, we have synthesized boehmite-lepidocrocite (AlOOH-FeOOH) composite nanorods mounted onto previously prepared graphene oxide (GO) surface (GO/AlOOH-FeOOH) by one step hydrothermal method. Then the prepared GO/A100H-FeOOH nanocomposite was sintered at 400 degrees C to form GO/Al2O3-Fe2O3 nanocomposite. Both the obtained GO functionalized nanocomposites were used as adsorbents for As(V) removal from water. The XRD, HRTEM confirmed the formation of gamma (AlOOH-FeOOH) and gamma (Al2O3-Fe2O3). TEM images revealed the formation of rod shape composite nanomaterials on GO surface. The GO/Al2O3-Fe2O3 showed magnetic properties with saturation magnetization value of 5.8emug(-1). Among the two prepared nanoadsorbents the GO/AlOOH-FeOOH shows better adsorption properties with maximum uptake capacity of 24.6 mgg(-1). The kinetics and isotherm experiments suggested that the adsorption process obeyed pseudo second order kinetic and Freundlich isotherm model. The presence of common coexisting anions including Cl-, SO42-, NO3- showed no significant effect on adsorption except PO43-. The mechanism of As(V) adsorption on GO/AlOOH-FeOOH includes electrostatic interaction and surface complexation reaction.