Enhanced photocatalytic performance of 2D/3D g-C3N4/MoS2 heterojunction for water remediation of real-world pollutants

Abstract

This study presents a highly efficient photocatalyst composed of hydrothermally synthesised g-C3N4/MoS2 heterostructures. Three-dimensional (3D) flower-like MoS2 nanostructures were combined with two-dimensional (2D) graphitic carbon nitride (g-C3N4) nanosheets. The synthesised g-C3N4/MoS2 heterostructures were utilised to evaluate their photocatalytic efficacy in degrading organic pollutants, including Rhodamine B (RhB), Methylene blue (MB), and the antibiotic Tetracycline (TC), under simulated solar light illumination. An optimized quantity of g-C3N4 in the g-C3N4/MoS2 heterostructures markedly improved the photocatalytic degradation efficiency, resulting in 99.9% degradation of RhB in 30 min, 99.9% degradation of MB in 10 min, and 94% degradation of TC in 40 min with a minimal catalyst dosage (0.20 mg/ml). The g-C3N4/MoS2 heterojunction showed remarkable efficacy in the concurrent degradation of RhB, MB, and TC in a mixed solution. The superior photocatalytic performance of the g-C3N4/MoS2 nanocomposites can be ascribed to multiple factors, such as enhanced light absorption, augmented specific surface area, and plentiful active sites for reactions. The establishment of a built-in potential at the g-C3N4/MoS2 interface, resulting from the heterostructure, enhances efficient charge carrier separation, encourages charge migration, and prolongs the lifespan of photoinduced electrons and holes. The photocatalytic mechanism is elucidated by the alignment of energy bands at the heterojunction interface, which improves electron-hole separation and transport. The results underscore the promise of the g-C3N4/MoS2 photocatalyst for wastewater treatment and environmental remediation applications.