Photocatalytic Degradation of Methylene Blue Dye over Indium Oxide Doped Nitrogen, Sulphur Anchored on rGO under Visible light Radiation

Abstract: Textile pollution is becoming a major contaminant and a concern that defies conventional water treatment procedures. Developing a method to remove these organic pollutants from the wastewater environment effectively is necessary. This research project aims to increase the photoactivity of Indium oxide (In₂O₃) towards removing methylene (MB) dye in wastewater by codoping with nitrogen, sulphur and reduced graphene oxide (N,S/rGO). Photocatalytic experiments were conducted to determine the degradation efficiency of MB dye under visible light in the presence of the as-prepared photocatalyst system. The results of the photodegradation rate study indicated that the In₂O₃/N,S-rGO nanocomposite degrades methylene blue (MB) dye faster than both pure In₂O₃and binary-doped In₂O₃. The kinetic model shows that the process is a pseudo-first-order kinetic. The rate constants (k) for the different photocatalysts were determined as 0.0035 min−1 for pure In₂O₃indicating the lowest activity, 0.0145 min−1 for In₂O₃-rGO, which shows medium activity and a maximum value of 0.0230 min−1 was obtained for the In₂O₃/N,S-rGO nanocomposite. In2O3-rGO nanoparticle doped with N,S exhibits the highest degradation efficiency of 94.8%, In₂O₃/rGO shows 71.3%, and bare In₂O₃shows the lowest degradation efficiency of 41.9% after 60 minutes of exposure to visible light.. This enhanced efficiency is due to the delocalization of electrons within the carbon framework of rGO, facilitated by the nitrogen and sulfur co-dopants, leading to increased photoactivity.