Mesoporous magnetic g-C₃N₄ nanocomposites for photocatalytic environmental remediation under visible light

Mesoporous magnetic Fe₃O₄/g-C₃N₄ nanocomposites were synthesized by a facile precipitation method using deionized water as solution. And the prepared magnetic materials were characterized by mean of various detection methods. At the same time, the photocatalytic activity of the synthetic material as photocatalyst under visible light was tested by taking the degradation of rhodamine B in water as a mark. Results show that as-synthesized Fe₃O₄/g-C₃N₄ nanocomposites have high specific surface areas of about 5-10.5 times that of pure g-C₃N₄ and high saturation magnetizations, which can ensure the smooth recovery of used nanomaterials under the action of external magnetic field. The addition of Fe₃O₄ greatly extents the response range of g-C₃N₄ nanomaterials to visible light and reduces the recombination rate of photoinduced electron-hole pairs. Meanwhile, the photocatalytic activity of the synthetic materials increases so that the degradation ratio of rhodamine B in water reached 97.6% after 4 h visible light irradiation. Furthermore, prepared magnetic Fe₃O₄/g-C₃N₄ nanocomposites have also excellent stability so that the degradation ratio of rhodamine B was almost not reduce after 5 times of continuous reuse of photocatalyst. Free radical scavenging experiments shows that hydroxyl groups are the main free radicals of photocatalytic reaction, peroxyradicals and holes play the secondary role. Therefore, it can be predicted that the synthesized mesoporous magnetic Fe₃O₄/g-C₃N₄ nanomaterials will have a broad application prospect in environmental remediation.