Hydrothermal Synthesis of Indium Oxide (In₂O₃) Semiconductor Photocatalyst Fabricated with Nitrogen-Sulfur Co-Doped Reduced Graphene Oxide (N,S-rGO)

Abstract

The main objective of this research project is to develop an efficient material for degrading pollutants from the textile and pharmaceutical industries, which seriously harm the environment and are challenging to remove from water bodies. This study aims to synthesize In₂O₃ and enhance its fundamental properties by fabricating it with a nitrogen and sulfur-reduced graphene oxide (N,S-rGO) heterostructure. Nanosized In₂O₃ was synthesized via a hydrothermal system and co-doped with N,S-rGO through a facile in-situ co-precipitation technique. The prepared samples were subjected to various characterization methods. XRD evaluation revealed that bare In₂O₃ has a rod-like structure with high crystallinity, while no characteristic diffraction peaks were observed for N,S-rGO and In₂O₃/N,S-rGO. FE-SEM and HR-TEM micrographs showed that In₂O₃ formed nanorods, N,S-rGO exhibited a thin-film layered structure, and In₂O₃/N,S-rGO presented a nanorod-layered structure. The nanorods had an average length of 200-500 nm, with particle sizes ranging from 1-4 μm. FT-IR spectra showed absorption peakscorresponding to In-O asymmetric vibrations and the in-planedeformation vibration of the O-H bond. Additionally, distinctvibrations corresponding to C=N, C-N, and C-S were noted. Astrong and broad absorption peak was observed in the UV-VISDRS evaluation, with a visible absorption edge at 460 nm forthe photocatalysts. Bandgap studies revealed a moderatereduction in bandgap from the bare to the binaryphotocatalyst, with the ternary composite showing the lowestbandgap of 2.72 eV. The characterization results suggest thatour In₂O₃/N,S-rGO nanocomposite is a feasible semiconductorphotocatalyst that is inexpensive, easy to assemble,environmentally friendly, and effective at addressing recyclingchallenges, charge recombination, surface area, and bandgapissues.