The current investigation focussed on the facile synthesis of MoS2/rGO nanocomposite with different weight percentages of MoS2 (1%, 5% and 15% w.r.t. to rGO) prepared via hydrothermal methods. The effective incorporation of MoS2 on the GO structures was substantially confirmed via various characterization tools via attenuated total reflectance-Fourier transform infrared (ATR-FTIR), ultraviolet-visible spectroscopy(UV–VIS), scanning electron microscope (SEM), transmision electron microscope (TEM), x-ray diffractometry (XRD), Raman spectroscopy, thermogravimetric analysis (TGA), surface area and pore analyzer, zeta potential and x-ray photoelectron spectroscopy (XPS). The nanocomposites were applied as photocatalysts to degrade perfluorooctanoic acid (PFOA) using a photoreactor equipped with an 18-watt fluorescent lamp. MoS2/rGO-15 showed superior photocatalytic properties for degrading PFOA, with kinetic rate constant k = 0.0758 min−1, and t ½ = 1.524 h under fluorescent light evaluated by using the Langmuir-Hinshelwood (L-H) model. The reusability studies indicated that the MoS2/rGO-15 composites can be reused for up to six cycles. Real water sample analysis revealed that MoS2/rGO-15 is efficient in degrading PFOA in a river water sample with a 77% degradation percentage. Thus, this research proposed a sustainable solution for photocatalytic degradation of PFOA in water purification under fluorescent light.