Recent advances in graphitic carbon nitride-based composites for enhanced photocatalytic degradation of rhodamine B: mechanism, properties and environmental applications

Abstract

Graphitic carbon nitride (g-C₃N₄), a photocatalyst responsive to visible light, shows remarkable promise for the effective photocatalytic decomposition of organic dyes. This can be attributed to its merits, such as low preparation cost and high stability. The synthetic dye Rhodamine B (RhB) poses serious ecological and health risks because it persists in aquatic environments because of its resistance to natural degradation. The purpose of this paper is to review the current breakthroughs in g-C₃N₄ modification. The main methods include surface functionalization and morphological engineering to increase visible light acquisition, suppress charge recombination, enhance visible-light absorption and optimize photocatalytic efficiency. An in-depth analysis of the key factors affecting the degradation of RhB by g-C₃N₄, including the catalyst dosage, solution pH, dye concentration, light conditions, catalyst stability and reusability, was performed. Mechanistic aspects highlight the key role of reactive oxygen species as well as interfacial charge transfer pathways in the system. Finally, to advance the use of g-C₃N₄-based photocatalysts in sustainable environmental remediation, future directions for material optimization and industrial applications are proposed.