Comparing the Degradation Potential of Copper(II), Iron(II), Iron(III) Oxides, and Their Composite Nanoparticles in a Heterogeneous Photo-Fenton System

Heterogeneous photo-Fenton systems offer efficient solutions for the treatment of wastewaters in the textile industry. This study investigated the fabrication and structural characterization of novel peculiar-shaped Cu(II)O, Fe(III)(2)O(3), and Fe(II)O nanoparticles (NPs) compared to the properties of the iron(II)-doped copper ferrite Cu(II)(0.4)Fe(II)(0.6)Fe(III)(2)O(4). The photocatalytic efficiencies of these NPs and the composite of the simple oxides (Cu(II)O/Fe(II)O/Fe(III)(2)O(3)) regarding the degradation of methylene blue (MB) and rhodamine B (RhB) as model dyes were also determined. The catalysts were synthesized via simple co-precipitation and calcination technique. X-ray diffractometry (XRD), scanning electron microscopy (SEM), and diffuse reflectance spectroscopy (DRS) were utilized for structural characterization. The structure of Cu(II)O was bead-like connected into threads, Fe(III)(2)O(3) was rod-like, while Fe(II)O pallet-like, with average crystallite sizes of 18.9, 36.9, and 37.1 nm, respectively. The highest degradation efficiency was achieved by Cu(II)O for RhB and by Cu(II)(0.4)Fe(II)(0.6)Fe(III)(2)O(4) for MB. The Cu(II)O/Fe(II)O/Fe(III)(2)O(3) composite proved to be the second-best catalyst in both cases, with excellent reusability. Hence, these NPs can be successfully applied as heterogeneous photo-Fenton catalysts for the removal of hazardous pollutants. Moreover, the simple metal oxides and the iron(II)-doped copper ferrite displayed a sufficient antibacterial activity against Gram-negative Vibrio fischeri.