Synergistic effect of boron and sulphur co-doping g-C<inf>3</inf>N<inf>4</inf> nanosheet/Ag<inf>2</inf>S heterojunctions for high-performance visible light-driven photocatalytic methylene blue

Abstract

The utilization of photocatalytic technology presents a promising solution to addressing the environmental issues. Scientists in the field of photocatalysis have consistently directed their efforts towards the improvement of visible light-sensitive photocatalysts that exhibit both high efficiency. The present study focuses on the investigation of an efficient, stable, and eco-friendly approach involving the co-doping of sulfur (S) and boron (B) in graphitic carbon nitride (g-CN) to support silver sulfide (Ag2S) composites (Ag2S/BSCN). The composites were prepared, characterized, and utilized as a photocatalyst for the degradation of methylene blue (MB) under visible light irradiation (VLI). The XRD, FTIR, HR-TEM, BET, XPS, UV-DRS, and PL characterizations were employed to validate the structural alterations resulting from Ag2S/BSCN composites. The HRTEM analysis revealed that the morphology of Ag2S/BSCN composites exhibited spherical Ag2S particles that were surrounded by a nano-sheet-like structure. The UV-DRS results show that incorporating Ag2S nanoparticles (NPs) and heteroatom-doped g-CN effectively enhances the nanocomposite's light response performance under VLI. Photoluminescence (PL) measurements demonstrate that the transport and separation efficiency of photogenerated carriers in Ag2S/BSCN have been significantly improved. In presence of VLI, the MB aqueous solution exhibits a high photodegradation efficiency of approximately 96.48 % after 90 min. Furthermore, the nanocomposite demonstrates remarkable catalytic stability during cyclic testing, highlighting its potential for the effective removal of organic pollutants. Further, the radical trapping experiments and degradation mechanism of MB is also discussed. The objective of this study is to explore a sustainable photocatalytic system that offers enhanced efficiency and stability for environmental applications.