Electronic, structural, optical, and photocatalytic properties of graphitic carbon nitride

Abstract

Graphitic carbon nitride (g-C₃N₄)-based materials exhibit an organized layered porous structure and a band position optimum for the development of various optoelectronic devices and photocatalysts. Hence, a considerable number of experimental and theoretical studies have been carried out to investigate their outstanding chemical and physical properties in both pristine and modified forms. In this study, we investigated the electronic, structural, optical, and photocatalytic properties of g-C₃N₄ obtained by heating urea in an appropriate self-supporting NH₃(g) atmosphere. The X-ray diffraction results revealed that the g-C₃N₄ nanopowder was crystalline and had a hexagonal structure. The crystallite size varied from 3.61 to 3.49 nm depending on the NH₃(g) concentration. The Fourier transform infrared analysis confirmed that g-C₃N₄ was synthesised successfully. The optical properties of g-C₃N₄ were investigated on the basis of its photoluminescence spectrum, which showed a broadband with blue region emission (∼490 nm). The decay time of g-C₃N₄ was used to evaluate its photocatalytic performance. An understanding of the structural defects in g-C₃N₄-based materials can provide an insight into their outstanding chemical and physical properties.