NiFe2O4/CuO heterostructures optical, magnetic and photocatalytic properties: Methylene blue dye degradation under solar light irradiation

Abstract

A series of NiFe2O4/CuO heterostructures were prepared and their photocatalytic potential was compared with bare NiFe2O4 (NFO) and CuO (CO). The prepared materials were subjected to characterization using a combination of X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), photoluminescence (PL) spectroscopy, and UV–visible (UV–Vis) spectroscopy techniques. Photocatalytic efficiency was studied for removing methylene blue (MB) dye under solar light irradiation. The NiFe2O4/CuO heterostructures demonstrated superior removal of MB dye versus other materials. The decline in PL intensity for heterostructure revealed a low recombination rate of charge carriers. Maximum dye removal over NiFe2O4/CuO heterostructure was achieved for 20 mg/L dye catalyst dose and 20 mg/L dye solution at pH 10. Scavenging studies showed that hydroxyl radicals and electrons played a major role in the degradation of dye. The removal efficiency was 80.01 %, which was reduced to 78.83 % for NiFe2O4/CuO heterostructures after four consecutive cycles, which indicates its high stability under solar light irradiation. The NiFe2O4/CuO heterostructures may find potential applications in water treatment for removing organic dyes under visible light owing to their robust catalytic performance under solar light irradiation.