Manganese ferrite-graphite oxide-chitosan nanocomposite for efficient dye removal from aqueous and textile wastewater under UV and sunlight irradiation
Nazila Mohammad Hosseini, Shabnam Sheshmani, Ashraf Sadat Shahvelayati
Abstract
This study presents the development and characterization of manganese ferrite (MnFe 2 O 4 )-based nanocomposites with graphite oxide (GO) and chitosan (CS) for efficient dye removal from textile wastewater and aqueous solution. Comprehensive characterization was performed using FT-IR, Raman, XRD, BET, SEM, DRS and Zeta potential techniques. XRD analysis confirmed the cubic spinel structure of MnFe 2 O 4 , with characteristic peaks at 2θ = 32, 35, 48, 53, 62, and 64°. BET analysis revealed a high specific surface area of 442.57 m 2 /g and a pore diameter of 2.36 nm for the MnFe 2 O 4 /GO/CS nanocomposite. SEM imaging showed polyhedral MnFe 2 O 4 particles (11–33 nm) deposited on a wrinkled graphite oxide matrix. DRS analysis indicated band gap energies of 3.1 eV for MnFe 2 O 4 , 3.0 eV for MnFe 2 O 4 /GO, and 3.5 eV for MnFe 2 O 4 /GO/CS. Zeta potential measurements showed a positive surface charge (+ 36.8 mV) for MnFe 2 O 4 /GO/CS. The MnFe 2 O 4 /GO/CS nanocomposite exhibited exceptional photocatalytic performance under UV light irradiation. It achieved 99.9 and 99.5% removal of Reactive Red 198 dye and Brilliant Blue FCF 133, respectively. The photocatalytic process followed pseudo-second-order kinetics (R 2 = 0.99). In real textile wastewater treatment, the nanocomposite reduced BOD from 889 to 0.86 mg/L and COD from 1227 to 74 mg/L, with 96% dye removal. Also, MnFe 2 O 4 /GO/CS showed excellent performance under sunlight irradiation and maintained high removal efficiencies over multiple cycles, demonstrating good reusability. This study highlights the potential of the MnFe 2 O 4 -based nanocomposites as versatile and sustainable solutions for remediating dye-contaminated water.