Visible-light-driven Z-scheme ternary Fe3O4/TiO2/g-C3N4 nanocomposite as reusable photocatalyst for efficient removal of dyes and chromium in water

In this work, a highly efficient magnetic recyclable Z-scheme ternary Fe3O4/TiO2/g-C3N4 heterojunction photocatalyst is designed through the hydrothermal method. The prepared photocatalysts were characterized by XRD, FTIR, Raman, TGA, BET, UV-vis DRS, PL, TEM, and XPS techniques. The superior photocatalytic degradation efficiency of ternary photocatalyst is about 98.2 and 95% for RhB and MB, respectively, under simulated solar light irradiation. The photocatalytic degradation rate constant of RhB and MB over ternary Fe3O4/TiO2/gC3N4 photocatalyst were 6.8, 7.5, and 2.4 folds higher (RhB); and 4.7, 7.8, and 3.4 folds higher (MB) than pure TiO2, pristine g-C3N4, and Fe3O4/TiO2 photocatalysts, respectively. Ternary photocatalyst also exhibits remarkable photocatalytic performance in the photoreduction of Cr(VI) with about 95.6% reduction efficiency attained in 50 min. The increase in photocatalytic activity of the ternary photocatalyst is accredited to the enhancement in electron-hole pair separation and the construction of the Z-scheme heterojunction structure. The simultaneous photodegradation and photoreduction of organic dyes and Cr(VI) reveal that ternary photocatalysts could be utilized in real-world wastewater applications.