A Novel Ternary Composite of GO/NiCoFe2O4/MIL-53 for Enhanced Copper Removal from Wastewater

Abstract

Excess copper levels have been associated with Alzheimer's disease, aging, mental illness, and DNA damage. As a result, the copper ions’ removal from water resources has become a major challenge. In this study, a novel ternary GO/NiCoFe₂O₄/MIL-53 composite was synthesized for the first time based upon a combination of GO, NiCoFe₂O₄, and MIL-53(Al) MOF, which effectively removed Cu²⁺ ions from aqueous solutions. The characterization was utilizing XRD, SEM/EDX, TEM, FT-IR, TGA, XPS, and BET analysis. XRD and FT-IR confirmed the formation of the GO/NiCoFe₂O₄/MIL-53 composite and Cu²⁺ adsorption. SEM images showed that MIL-53-MOF crystals have a rhombohedral crystal structure, while the NiCoFe₂O₄ particles have spindle-like crystals organized in flower-like shapes. The prepared GO/NiCoFe₂O₄/MIL-53 composite had a high specific surface area of 1235.58 m² g⁻¹ and exhibited characteristics of a mesoporous structure. The GO/NiCoFe₂O₄/MIL-53 composite showed high Cu²⁺ adsorption capacity of 90.09 mg g⁻¹ and reserved high removal ability even after five cycles. Different experimental factors like pH, initial-concentration, temperature, contact-time, ionic-strength, composite dosage, and coexisting-ions, were explored. The results showed that Cu²⁺ removal was fast and effective, with an efficiency exceeding 80 % within 30 minutes. The process of Cu²⁺ adsorption on the composite was exothermic, spontaneous, and followed the pseudo-second-order kinetics and Langmuir isothermal model. The Cu²⁺ recovery from water samples ranged between 86.5 %–94.3 %, indicating the excellent efficiency of the GO/NiCoFe₂O₄/MIL-53 composite for copper removal from real samples. Furthermore, the GO/NiCoFe₂O₄/MIL-53 composite established the best performance compared to other works for copper removal from wastewater.