Harnessing solar power for enhanced photocatalytic degradation of coloured pollutants using novel Mg-doped-ZnFe2O4/S@g-C3N4 heterojunction: A facile hydrothermal synthesis approach

Abstract

The ability of heterogeneous photocatalysis to effectively remove organic pollutants from wastewater has shown great promise as a tool for environmental remediation. Pure zinc ferrites (ZnFe₂O₄) and magnesium-doped zinc ferrites (Mg@ZnFe₂O₄) with variable percentages of Mg (0.5, 1, 3, 5, 7, and 9 mol%) were synthesized via hydrothermal route and their photocatalytic activity was checked against methylene blue (MB) taken as a model dye. FTIR, XPS, BET, PL, XRD, TEM, and UV-Vis spectroscopy were used for the identification and morphological characterization of the prepared nanoparticles (NPs) and nanocomposites (NCs). The 7% Mg@ZnFe₂O₄ NPs demonstrated excellent degradation against MB under sunlight. The 7% Mg@ZnFe₂O₄ NPs were integrated with diverse contents (10, 50, 30, and 70 wt.%) of S@g-C₃N₄ to develop NCs with better activity. When the NCs were tested to degrade MB dye, it was revealed that the 7%Mg@ZnFe₂O₄/S@g-C₃N₄ NCs were more effective at utilizing solar energy than the other NPs and NCs. The synergistic effect of the interface formed between Mg@ZnFe₂O₄ and S@g-C₃N₄ was primarily responsible for the boosted photocatalytic capability of the NCs. The fabricated NCs may function as an effective new photocatalyst to remove organic dyes from wastewater.

Keywords: MB; Mg@ZnFe2O4; nanocomposites; oxidation–reduction; photocatalysis.