The study investigated the photoactivity and enhancement effects of titania (TiO2) modified with La2S3 for wastewater pollutant removal. La2S3-TiO2 composite photocatalysts with different weight proportions of La2S3 to TiO2 were prepared via a hydrothermal synthesis approach. A comprehensive suite of analytical methods was employed to investigate the structural, morphological, compositional, and optical characteristics of the materials. These included X-ray diffraction (XRD) for crystallographic analysis, field emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDS) for surface morphology and elemental mapping, and high-resolution transmission electron microscopy (HR-TEM) for nanoscale structural insights. The specific surface area and porosity were determined through Brunauer-Emmett-Teller (BET) analysis, while optical absorption behavior was assessed using UV-visible diffuse reflectance spectroscopy (UV-DRS). Functional groups were identified through Fourier transform infrared spectroscopy (FT-IR), and the elemental composition and oxidation states were further evaluated by X-ray photoelectron spectroscopy (XPS). Their photocatalytic performance was assessed for the deterioration of Acid Red 14 (AR 14, carmoisine dye) in an aqueous solution under solar light. At pH 5, La2S3-TiO2 exhibited superior efficiency compared to stand-alone TiO2 and La2S3 for AR 14 mineralization. The effect of various operational conditions including catalyst loading, initial dye concentration, and solution pH on the photodegradation efficiency of AR 14 was systematically investigated. Active species trapping experiments identified holes, superoxide radical anions, and hydroxyl radicals as the main contributors to the photocatalytic process. COD measurements confirmed AR 14 mineralization, and the catalyst demonstrated reusability. Deterioration efficiency increased significantly with electron acceptors like H2O2 and K2S2O8. The kinetics of the photocatalytic process followed the Langmuir-Hinshelwood (L-H) model. Additionally, antibacterial activity tests showed that La2S3-TiO2 possesses promising antibacterial properties.