In2S3/Halloysite Nanocomposite as a Highly Efficient Photocatalyst for Oxidative Desulfurization of Dibenzothiophene in Fuel

Sulfur-containing organic compounds present in transportation fuels such as gasoline and diesel are a major source of environmental pollution, primarily due to the emission of sulfur oxides (SOₓ) during combustion. In response, increasingly stringent global regulations have been implemented to limit sulfur content in fuels. In this study, a nanocomposite photocatalyst composed of indium sulfide (In₂S₃) and halloysite was synthesized via a two-step hydrothermal process. The structural, morphological, and optical properties of the resulting photocatalysts were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and UV – Vis diffuse reflectance spectroscopy (UV – Vis DRS). The photocatalytic performance of the In₂S₃/Halloysite composite was evaluated through the oxidative desulfurization of dibenzothiophene (DBT) under visible light irradiation. Under optimized conditions — reaction temperature of 70 °C, 1.0 mL H₂O₂ as the oxidant, and 40 mg of photocatalyst — the DBT conversion reached 96% after 5 hours. These results highlight the potential application of In₂S₃/Halloysite nanocomposites as efficient visible-light-responsive photocatalysts for sulfur removal from fuels.