Visible LED-light driven photocatalytic activity by a novel magnetically separable CoFe2O4/Mn3O4 nanocomposite

Abstract

A novel magnetic separable CoFe₂O₄/Mn₃O₄ semiconductor catalyst was synthesized by sol-gel-cum-hydrothermal method, successfully. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman, and Fourier transformed infra-red spectrometers were used to characterize the prepared samples. Mn₃O₄ and CoFe₂O₄ exhibit in tetragonal and cubic phases, respectively. The obtained direct optical band gap of the samples belongs to the visible region. These catalysts were employed in photo-degradation of methylene blue (MB) dye under an LED visible light. Coupling of CoFe₂O₄ with Mn₃O₄, which formed type-II heterojunction, enhances the photocatalytic efficiency, provides magnetic separable features, and prevents the charge carriers’ recombination. Synthesized CoFe₂O₄/Mn₃O₄ nanocomposites show excellent photocatalytic activity with a high value of rate constant ∼ 0.03889 minute⁻¹. The scavenging test reveals that the holes and superoxide radicals were dominant reactive species in the degradation of dye. Magnetic separable feature of nanocomposite helps to recover the catalysts from degraded MB dye solution for the next photo-degradation cycles.