Green synthesis of Ni0.5Zn0.5AlFeO4 nanoparticles using Plantago major and photocatalytic degradation of reactive blue 21 dye under visible light irradiation.

[Display omitted] • Environment friendly synthesis of Ni 0.5 Zn 0.5 AlFeO 4 magnetic nanoparticles using Plantago major extract. • High photodegradation efficiency of Ni 0.5 Zn 0.5 AlFeO 4 magnetic nanoparticles for removing of RB 21dye. • Recycling of Ni 0.5 Zn 0.5 AlFeO 4 magnetic nano photocatalyst for removing of RB 21dye. The Ni 0.5 Zn 0.5 AlFeO 4 magnetic nanoparticles (MNPs) were synthesized using Plantago major seed extract via an environmentally friendly, efficient, low-cost, and simple process. The nanoparticles were characterized by FTIR, XRD, SEM, EDS, TEM, VSM, DRS, DLS, zeta potential analysis, and BET surface area analysis. The Ni 0.5 Zn 0.5 AlFeO 4 MNPs were examined as a catalyst for photodegradation of reactive blue 21 (RB 21). The results illustrated that the MNPs were efficient for the photodegradation of RB 21. The catalyst eliminated about 92% of RB 21 after 40 min (30 mg of catalyst dosage at a concentration of 20 ppm for RB 21). The band gap of Ni 0.5 Zn 0.5 AlFeO 4 MNPs computed by DRS was 1 eV. The XRD analysis showed a cubic spinel structure without any impurity phases with a crystallite size of about 10 nm. The zeta potential analysis and DLS indicated some agglomerations in the solvent. The hot filtration test showed that the reaction was heterogeneous. The kinetics for photodegradation of RB 21 on Ni 0.5 Zn 0.5 AlFeO 4 MNPs follow the first-order kinetics model. [ABSTRACT FROM AUTHOR]