Facile synthesis and enhanced visible-light photocatalytic activity of graphitic carbon nitride decorated with ultrafine Fe2O3 nanoparticles

Abstract

Hybrid nanocomposites based on graphitic carbon nitride (g-C₃N₄) nanosheet supported ultrafine Fe₂O₃ nanoparticles have been successfully prepared by a facile thermal polymerization and deposition-precipitation method. Characterization results demonstrate that Fe₂O₃/g-C₃N₄ nanocomposites exhibit a well-defined morphology, in which Fe₂O₃ nanocrystals of 3 nm size with a narrow particle distribution are uniformly dispersed on the layers of the g-C₃N₄ nanosheets. Photocatalytic reaction results indicate that the photocatalytic activity of g-C₃N₄ is significantly enhanced after introduction of a small amount of Fe₂O₃, and the optimum activity of the Fe₂O₃/g-C₃N₄ nanocomposites with a weight ratio of Fe₂O₃ at 0.1% is up to about 3 times and 62 times higher than those of pure g-C₃N₄ and pure Fe₂O₃, respectively, for the degradation of organic dye Rhodamine B (RhB) under visible light irradiation. The high performance of the Fe₂O₃/g-C₃N₄ photocatalysts is mainly attributed to the synergistic effect at the interface of the heterojunction between Fe₂O₃ nanoparticles and g-C₃N₄ nanosheets, including improved separation efficiency of the charge carriers, a suppressed recombination process and suitable band position of the composites. These results underline the potential for the development of effective, low-cost and earth-abundant photocatalysts for the promotion of water splitting and environmental remediation under natural sunlight by construction of sustainable g-C₃N₄ polymeric materials.