This paper reports an assessment of the photocatalytic activity of TiO₂ nanotubes (TNTs) doped with strontium titanate (SrTiO₃) and sulfur (S) with respect to the decomposition of methylene blue (MB). TNT was obtained by the double anodizing method with further doping of strontium titanate by the hydrothermal method and additional annealing in an atmosphere of N₂ (95%) + H₂S (5%) at 450–550 °C. The photocatalytic activity was evaluated using MB as a pollutant and this study was conducted using an Osram Vita-Lux lamp with a power of 300W as a visible light source. The photocatalytic abilities of the synthesized materials were investigated, and characterized by methods such as SEM, TEM, XRD, EDS, and UV–Vis spectroscopy. Our study showed that the SrTiO₃/TiO₂NT@S composite has a better photocatalytic decomposition ability for the dye under consideration compared to pure TNT and SrTiO₃/TiO₂NT. These results clearly demonstrate the potential of synthesized SrTiO₃/TiO₂NT@S material for applications in water purification and photocatalysis.