This review explores the use of titanium dioxide (TiO₂)-based photosensitizers to enhance the photocatalytic removal of thiazine dyes from water, particularly methylene blue (MB). Thiazine dyes, common in industrial effluents, pose environmental concerns due to their persistence and toxicity. TiO₂, known for its exceptional photocatalytic properties, has a wide bandgap that limits its responsiveness to visible light. The integration of thiazine dyes as photosensitizers in TiO₂ materials addresses this issue by extending the light absorption spectrum into the visible region. This review highlights the mechanisms of light absorption and energy transfer between dye sensitizers and TiO₂, emphasizing the role of electron-hole pair separation and the generation of reactive oxygen species (ROS). The synergy between dye sensitizers and TiO₂ enhances the overall efficiency of processes such as dye degradation and water splitting. Thiazine dyes, with their unique properties, offer valuable applications in wastewater treatment, solar energy conversion, and environmental remediation. However, the toxicity and non-biodegradability of thiazine dyes must be carefully considered in their application and disposal. The review also discusses the advantages and disadvantages of using thiazine dyes as photosensitizers, including their potential environmental impact and therapeutic benefits in photodynamic therapy (PDT). Overall, the integration of TiO₂-based photosensitizers represents a promising approach for sustainable and efficient environmental solutions.This review explores the use of titanium dioxide (TiO₂)-based photosensitizers to enhance the photocatalytic removal of thiazine dyes from water, particularly methylene blue (MB). Thiazine dyes, common in industrial effluents, pose environmental concerns due to their persistence and toxicity. TiO₂, known for its exceptional photocatalytic properties, has a wide bandgap that limits its responsiveness to visible light. The integration of thiazine dyes as photosensitizers in TiO₂ materials addresses this issue by extending the light absorption spectrum into the visible region. This review highlights the mechanisms of light absorption and energy transfer between dye sensitizers and TiO₂, emphasizing the role of electron-hole pair separation and the generation of reactive oxygen species (ROS). The synergy between dye sensitizers and TiO₂ enhances the overall efficiency of processes such as dye degradation and water splitting. Thiazine dyes, with their unique properties, offer valuable applications in wastewater treatment, solar energy conversion, and environmental remediation. However, the toxicity and non-biodegradability of thiazine dyes must be carefully considered in their application and disposal. The review also discusses the advantages and disadvantages of using thiazine dyes as photosensitizers, including their potential environmental impact and therapeutic benefits in photodynamic therapy (PDT). Overall, the integration of TiO₂-based photosensitizers represents a promising approach for sustainable and efficient environmental solutions.