Synthesis of Graphitic Carbon Nitride on the Surface of Fe3O4 Nanoparticles

A composite material consisting of graphitic carbon nitride and iron(II,III) oxide (g-C3N4/Fe3O4) and having photocatalytic and magnetic properties has been synthesized via single-step thermal decomposition of melamine in the presence of Fe3O4 nanoparticles. It has been shown that, at synthesis temperatures in the range 400-500 degrees C, Fe2+ ions do not oxidize, and the Fe3O4 particles retain their crystal structure and ferromagnetic properties, but the process involves the formation of crystalline g-C3N4 as well. The maximum in the intensity of photoluminescence bands of the g-C3N4/Fe3O4 composite material is shifted to lower photon energies compared to g-C3N4 prepared without Fe3O4 particles under the same synthesis conditions, which is due to a decrease in its band gap, formed by a system consisting of C-N pi bonds with sp(2) hybridization. The magnetic properties of g-C3N4/Fe3O4 composite particles allow them to be readily recovered from liquids for reuse.