<p>In this study, Fe₂O₃/TiO₂ nanocomposite was synthesized via a hydrothermal method and evaluated for its dual functionality in visible-light-driven photocatalytic dye degradation and electrochemical nitrite sensing. Structural, optical, and morphological characterizations confirmed the formation of a well-defined heterojunction with improved charge separation and visible light absorption. The nanocomposite demonstrated enhanced photocatalytic performance, achieving 100% degradation of methylene blue (MB) within 120 minutes under visible light. Kinetic studies confirmed pseudo-first-order behavior with an increased rate constant compared to individual TiO₂ and Fe₂O₃ components. Furthermore, the Fe₂O₃/TiO₂ modified glassy carbon electrode exhibited excellent electrocatalytic activity for nitrite detection, achieving a low detection limit of 1.4 µM with a linear response over a wide concentration range. These findings highlight the potential of Fe₂O₃/TiO₂ nanocomposites as multifunctional materials for environmental remediation and chemical sensing applications.</p> Graphical Abstract <p></p>