One-pot synthesis of water-swellable Mg-Al layered double hydroxides and graphene oxide nanocomposites for efficient removal of As(V) from aqueous solutions.

In this Article, we report a remarkably simple and efficient method for the preparation of layered double hydroxides and graphene oxide (LDHs/GO) nanocomposites with varying GO amounts via a hydrothermal process. The graphene nature in the resulting LDHs/GO nanocomposites was confirmed by X-ray diffraction (XRD), Fourier transformed infrared (FTIR) spectroscopy, field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), N2 adsorption-desorption, and X-ray photoelectron spectroscopy (XPS). The LDHs/GO nanocomposites exhibited swelling behavior in water and forming a gel. The adsorption performance of the LDHs/GO nanocomposites was evaluated for the removal of arsenate (As(V)) from aqueous solutions, and the results showed that the ratio of GO to LDHs in the nanocomposites significantly affected the adsorption capacity. Higher and lower amounts of GO in LDHs/GO nanocomposites showed lower adsorption capacity of As(V). A maximum adsorption capacity of 183.11 mg/g (2.44 mmol/g) was achieved on the LDHs/GO containing 6.0% GO due to the higher Brunauer-Emmett-Teller (BET) surface area than other samples. Owing to their high uptake capability of As(V), water-swellable LDHs/GO nanocomposites are expected to have potential applications as adsorbents for As(V) polluted water cleanup.