Solvothermal Synthesis of Magnetic CoFe₂O₄/Carbon Nanocomposites with Superior Visible Light Photocatalysis

In order to enhance the photocatalytic performance of CoFe₂O₄, carbon (C) was exploited to modify it through developing a CoFe₂O₄/C heterojunction photocatalyst. CoFe₂O₄/C nanocomposites with varying C contents were fabricated through a simple one-pot solvothermal approach by adjusting the dosage of glucose. The photocatalytic capabilities of the as-prepared CoFe₂O₄/C nanocomposites were evaluated by the reduction of Cr(VI) under visible light exposure. The experimental results indicated that all of the as-prepared CoFe₂O₄/C products had substantially greater photocatalytic Cr(VI) reduction activity than CoFe₂O₄, with CoFe₂O₄/C-2 being the optimal photocatalyst. CoFe₂O₄/C-2 not only showed a photocatalytic activity 6.7 times greater than that of CoFe₂O₄, but it also outperformed a considerable number of previously reported visible light photocatalysts. Furthermore, the appropriate optimization of the photocatalytic experiment parameters could further improve the photocatalytic Cr(VI) reduction rate of CoFe₂O₄/C-2. In addition, CoFe₂O₄/C-2 also exhibited superior photocatalytic stability. Another advantageous feature of CoFe₂O₄/C-2 is its easy recoverability from water through a simple magnetic attraction. The remarkably enhanced photocatalytic activity of CoFe₂O₄/C-2 is primarily ascribed to the improved separation and transfer of photogenerated charges, which is a result of its p-n heterojunction structure. This study offers a valuable reference for the synthesis and application of a highly efficient magnetic CoFe₂O₄/C photocatalyst for treating Cr(VI) contamination in water bodies.