Eco-friendly Activated Carbon Thin Film-Zeolitic Imidazolate Framework-8 (ACTF@ZIF-8) Nanocomposite for Efficient Methylene Blue Removal: Synthesis, Characterization, and Adsorption Performance

Abstract

The extensive use of synthetic dyes in the textile industry has resulted in severe water contamination, with methylene blue (MB) being a prevalent pollutant. This study presents the development of an eco-friendly nanocomposite, Activated Carbon Thin Film-Zeolitic Imidazolate Framework-8 (ACTF@ZIF-8), synthesized through an in-situ growth method for efficient MB removal from aqueous solutions. The composite's structural and physicochemical properties were thoroughly characterized using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), X-ray Diffraction (XRD), High-Resolution Transmission Electron Microscopy (HR-TEM), and Brunauer-Emmett-Teller (BET) surface area analysis. The nanocomposite exhibited a high specific surface area of 384.4 m²/g and an adsorption capacity of 156.83 mg/g, achieving a removal efficiency of 98.8%. Kinetic studies indicated that MB adsorption followed a pseudo-second-order model (R² = 0.9994), suggesting chemisorption as the primary mechanism. The adsorption isotherms conformed to the Freundlich model (R² = 0.999), indicating multilayer adsorption on a heterogeneous surface. Thermodynamic analysis indicated an endothermic process, characterized by a positive enthalpy change and an increase in entropy. The process was confirmed to be spontaneous, as demonstrated by negative Gibbs free energy values. The composite also demonstrated high reusability, maintaining efficiency across multiple cycles. These findings position ACTF@ZIF-8 as a promising material for sustainable wastewater treatment, aligning with advancements in nanomaterial-based environmental remediation.