Insights into charge transfer via Z-scheme for Rhodamine B degradation over novel Co3O4/ZnFe2O4 nanocomposites

So far, the waste water treatment through the dye degradation by the photocatalysis has been acknowledged as one of the promising techniques. In this connection, a novel (1-x)Co3O4-xZnFe2O4 (where x = 0.05, 0.10, 0.20, 0.30 and 0.50 wt%) nanocomposite based photocatalysts was successfully built using a hydrothermal method and were thoroughly examined by means of X-ray diffraction (XRD), Field Emission Scanning Electron Micro-scopy (FESEM), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (DRS), Brunauer-Emmett-Teller (BET) and photoluminescence (PL) techniques. The research outcome unveiled the fact that most of the Co3O4/ZnFe2O4 composites were highly efficient as compared with pristine Co3O4 and ZnFe2O4 in Rhodamine B degradation. The 0.80Co3O4/0.20ZnFe2O4 exhibited the superior photocatalysis via Z scheme rather than Type-II charge transfer with 93% dye degradation within 240 min under UV light. According to PL results, 0.80Co3O4/0.20ZnFe2O4 composite showed the lowest charge recombination and corroborated with the tendency of Rh B degradation. The performed trapping tests distinctly identified the roles of various radicals. The 0.80Co3O4/0.20ZnFe2O4 composite has high reusable efficiency. The plausible mechanism of improvement in photocatalysis of these nanocomposites was comprehensively under-stood through the precisely computed energy band potentials.

Automated summary

Waste water treatment through photocatalysis is a promising technique for dye degradation. In this study, nanocomposite photocatalysts (1-x)Co3O4-xZnFe2O4 were successfully synthesized and tested for Rhodamine B degradation. The 0.80Co3O4/0.20ZnFe2O4 composite showed the highest photocatalytic efficiency with 93% dye degradation in 240 minutes through a Z scheme mechanism.