Graphene Oxide Nanocomposite Decorated Zeolitic Imidazolate Framework-8 As an Effective Sorbent for Acid Orange 10 Dye Removal Publisher



N Kadkhodaie NARGES ; A Ebrahimi AFSHIN ; M Moazeni MALIHE ; A Fatehizadeh ALI ; S Rtimi SAMI
Source: Colloids and Surfaces A: Physicochemical and Engineering Aspects Published:2025

Abstract

Global industrialization is associated with the release of high amounts of toxic pollutants, such as synthetic dyes, into the environment. Zeolitic imidazolate frameworks (ZIFs), a subclass of metal-organic frameworks (MOFs), are renowned for their exceptional chemical and thermal stability, making them promising candidates for pollutant's adsorption. In this study, a ZIF-8/graphene oxide (GO) composite was synthesized via a hydrothermal method at three ZIF-8 to GO ratios (5 %, 10 %, and 15 %) to enhance the sorption of acid orange 10 dye (AO10). The ZIF-8/GO (10 %) composite exhibited high crystallinity, a specific surface area of 418 m²/g, and functional groups (e.g., hydroxyl and carboxylate (O–H and COO–)), which facilitated superior dye sorption. Under optimal conditions (pH = 3, sorbent dose = 4.8 mg/L, AO10 concentration = 5 mg/L, reaction time = 90 min), the composite achieved complete (100 %) removal of AO10. The sorption process followed the Freundlich isotherm model, indicating multilayer sorption on heterogeneous surfaces, with a maximum sorption capacity (qe) of 6780–7250 mg/g. Kinetic studies revealed pseudo-first-order behavior (kf = 0.15–0.18 min−1), suggesting physisorption as the dominant mechanism, supplemented by π–π interactions and electrostatic forces between the sulfonate groups of AO10 and the positively charged ZIF-8/GO surface. These results highlight the composite's novelty as a high-capacity, fast-acting sorbent for wastewater treatment, addressing critical challenges in dye pollution remediation. © 2025 Elsevier B.V., All rights reserved.