Water desalination using stainless steel meshes coated with layered double hydroxide/graphene oxide nanocomposite

Abstract

AbstractCoated stainless steel meshes with layered double hydroxides and graphene oxide nanocomposites (LDH/GO) were used as desalination membranes. The nature of stainless steel mesh allows a greater amount of sorbent to be coated on the surface using sol–gel technique and increases the adsorption capacity of ions and the efficiency of desalination. These substrates improve the contact surface area so that approximately 5 min is required for the desalination process. The LDH/GO stainless steel mesh exhibited excellent corrosion resistance and tensile strength of 99.9% and 112 MPa, respectively. To achieve the best desalination efficiency, different parameters were optimized, including the ratio of GO to LDH in the nanocomposites, the number of mesh layers, NaCl concentrations, and process cycles. The maximum adsorption capacity for the NaCl was 555.5 mg g−1. The results revealed that LDH/GO nanocomposite was able to remove (94.3 ± 0.5) % of the NaCl under the optimum conditions. The proposed method was used to successfully remove Na+, Mg+2, Ca+2, and K+ cations from seawater, with the yields of 92.3%, 92.5%, 91.2%, and 90.2%, respectively.Practitioner Points The salts are removed via interaction between salt ions and functional groups on the LDH/GO nanocomposite surface. A high amount of adsorbent loaded on the surface of steel mesh leads to an improvement in the adsorption capacity. The sol‐gel technique strengthens the LDH/GO nanocomposites on the surface of steel mesh.