2D-3D magnetic NiFe layered double hydroxide decorated diatomite as multi-function material for anionic, cationic dyes, arsenate, and arsenite adsorption

Three-dimensional diatomite was decorated with a novel magnetic two-dimensional layered double hydroxides nanosheet (DE@NiFe LDH) by the hydrothermal synthesis method. The adsorption of anionic, cationic dyes, As (V), and As(III) was achieved by the synergistic effect of diatomite and NiFe LDH. The newly synthesized ma-terials were characterized by different methods: XRD; FT-IR; zeta potential measurements; N2 adsorption to determine surface area and pore structure; SEM and XPS. The effects of pH, concentrations, contact time and temperature on the adsorption properties were also studied to clarify the mechanism. At adsorption equilibrium (1 h), the adsorption of methyl orange, and methylene blue reached 96.8% and 84.4%, respectively. Maximum sorption of MO, MB, As(III), and As(V) was 134.32, 76.79, 335.69, and 80.58 mg g-1 respectively, exhibiting superior adsorption performance. The thermodynamic parameters of the adsorption process were calculated and indicated that the adsorption process is exothermic. This work provides an idea for the synthesis of low-cost, ideal, and magnetic multifunctional nano adsorbent for anionic, cationic dyes, As(V), and As(III), offering po-tential applications for practical wastewater purification.