Synthesis and characterization of novel halloysite-agar-Ni0.5Zn0.5Mn2O4 composite for efficient methylene blue dye removal

Abstract

In this research work, An innovative halloysite-agar -Ni₀.₅Zn₀.₅Mn₂O₄ nanocomposite was successfully synthesized by incorporating halloysite and Ni_0.5Zn_0.5Mn₂O₄ into agar networks through cross-linking with Epichlorohydrin. FTIR, XRD, TGA/DTA, SEM-EDS methods were used to characterize the synthesized nanocomposite. In addition, the swelling rate and PHpzc of the product obtained were also studied. FTIR analysis revealed the presence of functional groups associated with all components and XRD revealed that adding halloysite to the agar matrix significantly improved the thermal stability of the composite compared to its constituents. The Halloysite/Agar/Ni_0.5Zn_0.5Mn₂O₄'s porous structure was evident in the SEM investigation, which contributed to its high adsorption capacity. The analysis of the swelling characteristics showed that the percentage of swelling of the hydrogel attained a maximum ratio of 939,3 % in water. This high swelling capacity contributed to the excellent adsorption performance of the nanocomposite. The nanocomposite obtained was applied as an adsorbent for eliminating methylene blue which was chosen as a model for cationic dyes. It demonstrated a remarkable adsorption capacity of 130 mg/g for this dye under the optimal conditions: 60 g/l agar, Epichlorohydrin (0.1 M), 20 % halloysite and 20 % Oxide, at PH= 6 and ambient temperature.