Bimetallic Metal-Organic Framework Decorated 3D-electrospun Nanofibers as a Highly Efficient Sorbent for Removing Organic Dyes from Contaminated Water

Background: Recently, bimetallic metal-organic frameworks (MOFs) have gained significant attention for their potential in treating industrial wastewater. The rapid increase in industrialization worldwide has resulted in the continual discharge of organic dyes in aquatic ecosystems. These dyes disrupt aquatic ecosystems and are hazardous for human beings. Thus, there is a considerable demand to design a framework for the removal of contaminants from wastewater. For this purpose, this study focuses on synthesizing BM-MOF@PC and investigating its efficacy in removing methyl orange (MO) and congo red (CR). Methods: A novel, low-cost, eco-friendly Zn and Co-based bimetallic MOF (BM-MOF) modified polyaniline and cellulose acetate (PC) were synthesized based on electrospun (BM-MOF@PC) nanofibers. The prepared BM-MOF@PC was characterized by SEM, XRD, FTIR, and N2 adsorption-desorption isotherm. The smooth formation of BM-MOF@PC nanofibers generates high adsorption capability by exposing the maximal active site for the adsorption at the entire surface. The adsorption capability of synthesized BM-MOF@PC nanofibers was evaluated against MO and CR dyes from an aqueous phase. Results: The maximum adsorption capacity of MO and CR at the surface of BM-MOF@PC nanofibers were 636.9 and 313.05 mg/g, respectively. Several adsorption parameters, including initial dye concentration, contact time, temperature, the adsorbent's doses, and pH's effect on adsorption kinetics, were investigated. The ability of BM-MOF@PC nanofibers to adsorb MO and CR at various pHs indicated that several attraction forces, including electrostatic interaction, hydrogen bonding, and π-π interactions, could be involved in the dye removal. Conclusion: The fabricated material BM-MOF@PC nanofibers have a large surface area compared to BM-MOF, which indicates the more active sites for the adsorption of MO and CR dyes. Moreover, the BM-MOF@PC nanofibers demonstrated robust reusability towards MO and CR adsorption across five cycles, which suggested that our fabricated material is more stable and economically reliable in real-time applications.