Psidium guajava leave-based magnetic nanocomposite γ-Fe2O3@GL: A green technology for methylene blue removal from water

This study reports the incorporation of magnetic gamma-Fe2O3 nanoparticles into the carbon framework of highly abundant, house hold medicinal plant, Psidium guajava, commonly known as Guava through co-precipitation. The prepared nanocomposite, gamma-Fe2O3@GL was characterized with several spectroscopic and microscopic techniques, and showed the nano-porous structure having extensive oxygenous functional groups at the surface. The saturation magnetic moment of gamma-Fe2O3@GL was found to be 0.72 emug(-1). Nanocomposite was used for the adsorption of methylene blue from water for which batch experiments were carried out under the change of various process parameters, and exhibited the fast and 99% removal of methylene blue from its solution having 10 mg L-1 concentrations with 1.0 gL(-1) amount of gamma-Fe2O3@GL. The maximum monolayer adsorption capacity was found to be in range 69.93 to 91.74 mgg(-1), at 27-45 degrees C. The magnetically separable gamma-Fe2O3@GL showed the high reusability and adsorption rate without significant loss after sixth adsorption-desorption cycles. Therefore, the prepared magnetic gamma-Fe2O3@GL can be useful technique for water treatment having low cost and high adsorption capacity.