Methyl orange dye removal using Ni/Fe-NO3 and Ni/Fe-[α-SiW12O40] layered double hydroxides

Abstract

Abstract The material of layered double hydroxide (LDH) Ni/Fe-NO3 was prepared by coprecipitation method under basic condition. Ni/Fe LDH was modified by intercalation using K4[α-SiW12O40] to form Ni/Fe-[α-SiW12O40]. All materials were characterized by X-ray and FTIR spectroscopy. Ni/Fe LDH and intercalated Ni/Fe LDH were used as adsorbent of methyl orange dye from the aqueous solution. The parameter of adsorption such as kinetic and also thermodynamic adsorption of methyl orange on LDHs were investigated. X-Ray analysis showed that the diffraction at 11.53 ° [003] of Ni/Fe-NO3 has interlayer distance 7.67 Å shift to 8.20 ° [003] of Ni/Fe-[α-SiW12O40] with interlayer distance 10.78 Å. FTIR spectra of Ni/Fe-NO3 and Ni/Fe-[α-SiW12O40] show the wavenumber at 1600 cm−1 due to vibration of LDHs anion. Adsorption of methyl orange onto Ni/Fe-NO3 and Ni/Fe-[α-SiW12O40] follow the pseudo second-order kinetic model, where intercalated material has a higher reactivity than Ni/Fe-NO3 before intercalation. Isotherm model Freundlich was more fitted than isotherm Langmuir for the adsorption of methyl orange on LDHs with multilayer physical adsorption process. Adsorption capacity of methyl orange on Ni/Fe-[α-SiW12O40] as adsorbent was slightly higher (up to 7.226 mg.g−1) than Ni/Fe-NO3 as adsorbent (3.190 mg.g−1).