Improved adsorption of Fuschin Blue with Sn2+ impregnated Zn-Bi mixed metal hydroxide

Abstract

The issue of water contamination resulting from textile dyes has garnered public attention. To address this issue, a new highly stable, greener, nontoxic composite material (ZBH.Sn) consisting of Sn²⁺ doped Zn-Bi mixed metal hydroxide (ZBH) was effectively fabricated. The adsorbent underwent a thorough investigation of its structural and morphological properties utilizing XRD, HR-TEM, FE-SEM, FTIR, XPS, Zeta, and DLS. XRD confirms the crystallinity of mixed phases of both zinc and bismuth hydroxides. The hexagonal sheet-like morphology is evident in SEM, and elemental mappings show that individual elements are evenly distributed on the external surface. The ZBH.Sn adsorbent demonstrates an adsorption efficiency in the removal of Fuschin blue (F.B.) from wastewater systems. With optimized 2.5 mg ZBH.Sn in 20 mL (0.05 mM) of F.B concentration at pH 6, the maximum adsorption capacity was 80.56 % in 180 minutes at 298 K. The detailed thermodynamic information (ΔG= −2.477 KJ/mol) including adsorption maximum capacity q_max (1472.75 mg/g), adsorption equilibrium constant (k₂= 3.7×10⁵ g.mg¹.min¹), and adsorption efficiency (80.56 %) were obtained to evaluate the different reaction performances for F.B by ZBH.Sn. Such observation suggests that these materials could serve as effective adsorbents for removing F.B. from wastewater because of their high adsorption capabilities and low cost.