Z-scheme ZnFe2O4/CeO2 nanocomposites with enhanced photocatalytic performance under UV light

The motivation of this work is to identify structural, optical, magnetic properties of ZnFe2O4/ CeO2 nanocomposites and their potential use in removal of water-polluting dye. The cost-effective hydrothermal technique was used to synthesize ZnFe2O4/ CeO2 nanocomposites of different weight ratio (1:1, 1:2, 1:3, and 1:4). XRD pattern of synthesized samples show two different phases corresponding to ZnFe2O4 and CeO2, respectively. FTIR spectra enlightened Zn-O, Fe-O, and O-Ce-O bonds in synthesized nanocomposites. Further UV-Vis spectroscopy demonstrated that band gap varies from 2.17 to 3.12 eV. This change may be attributed to creation of new sub-band gap energy levels upon addition of wide band gap semiconductor (CeO2). Magnetic investigations showed that pure ZnFe2O4 has greater magnetic character than other synthesized materials, with a maximum magnetization of 1.42 emu/g. HRTEM analysis showed spherical morphology of synthesized samples. In comparison to single metal oxides (ZnFe2O4 and CeO2), maximum photodegradation efficiency of ZnFe2O4/ CeO2 (1:4) nanocomposites for Rose Bengal dye was observed to be 95% in 75 min. Furthermore, photocatalytic activity remains unchanged after four runs for this photocatalyst, allowing the reusability of catalysts. In nanocomposites, Ce4+/ Ce3+ redox couple and heterojunction interfaces have encouraged electron transport and photo-excited electron-hole recombination which ultimately affects photodegradation efficiency of nanocomposites.

Automated summary

The work aimed to identify the properties of ZnFe2O4/ CeO2 nanocomposites and their potential use in water pollution dye removal. The nanocomposites were synthesized using a cost-effective hydrothermal technique, and their structural, optical, and magnetic properties were studied. The results showed that the nanocomposites had a high photodegradation efficiency for dyes and the catalysts were reusable.