Photocatalytic activity of α-Fe2O3@CeO2 and CeO2@α-Fe2O3 core-shell nanoparticles for degradation of Rose Bengal dye

Core-shell structures of mixed oxides have great interest due to their physical and chemical properties. The present study aims to determine the structural, magnetic, and optical characteristics of the core-shell structure of alpha-Fe2O3@CeO2 and CeO2@alpha-Fe2O3 nanoparticles and their application in the purification of dye contaminates water. These core-shell nanoparticles were synthesized by the cost-effective hydrothermal method with weight ratios as alpha-Fe2O3:CeO2 (1:1, 2:1) and CeO2:alpha-Fe2O3 (1:1, 1:2). XRD pattern revealed two distinct phases corresponding to Fe2O3 and CeO2 in synthesized core-shell structures. Defects/oxygen vacancies in lattice were determined using XPS spectra. Magnetic studies indicate that the magnetic character of pure Fe2O3 was found higher with maximum magnetization of 0.84 emu/g than other synthesized materials due to the contribution of non-magnetic CeO2. The maximum photodegradation efficiency of core-shell nanoparticles [alpha-Fe2O3@CeO2 (2:1)] for Rose Bengal dye was found to be 93% in 75 min under UV irradiation source as compare to the single metal oxides i.e., alpha-Fe2O3 and CeO2. The Ce4+/Ce3+ and Fe2+/Fe3+ redox couple and heterojunction interfaces of core-shell material have promoted electron transfer and photo-excited electron-hole recombination. These properties of core-shell materials are significant for the photodegradation of Rose Bengal dye.

Automated summary

This study successfully synthesized α-Fe2O3@CeO2 and CeO2@α-Fe2O3 core-shell nanoparticles for the first time using a hydrothermal method. Characterization was done using XRD patterns and XPS spectra, revealing the magnetic properties and defects/vacancies in lattice. The core-shell nanoparticles showed higher magnetic character for pure Fe2O3 and higher photodegradation efficiency compared to single metal oxides.