Synthesis of Graphitic Carbon Nitride on the Surface of Fe 3 O 4 Nanoparticles

— A composite material consisting of graphitic carbon nitride and iron(II,III) oxide ( g- C 3 N 4 /Fe 3 O 4 ) and having photocatalytic and magnetic properties has been synthesized via single-step thermal decomposition of melamine in the presence of Fe 3 O 4 nanoparticles. It has been shown that, at synthesis temperatures in the range 400–500°C, Fe 2+ ions do not oxidize, and the Fe 3 O 4 particles retain their crystal structure and ferromagnetic properties, but the process involves the formation of crystalline g -C 3 N 4 as well. The maximum in the intensity of photoluminescence bands of the g- C 3 N 4 /Fe 3 O 4 composite material is shifted to lower photon energies compared to g -C 3 N 4 prepared without Fe 3 O 4 particles under the same synthesis conditions, which is due to a decrease in its band gap, formed by a system consisting of C–N π bonds with sp 2 hybridization. The magnetic properties of g- C 3 N 4 /Fe 3 O 4 composite particles allow them to be readily recovered from liquids for reuse.