Heterogeneous photocatalysis is a promising technology to overcome the problems associated with the energy crisis and environmental pollution. Therefore, the design of a reusable dual function photocatalyst has been studied extensively. Herein, MIL-53 (Fe) was used to fabricate Fe₃O₄@C on which TiO₂ was deposited via a sol-gel route to form Fe₃O₄@C@TiO₂ (FCT) double core-shell nanocomposite. Thermal treatment effect on photocatalytic activity under different atmospheres (air, argon and hydrogen) has been investigated. Then, the temperature was optimized (300-400 °C) under hydrogen atmosphere. Furthermore, the photocatalytic performance of the prepared composite on Rose Bengal (RB) dye degradation and hydrogen generation via water-splitting has been evaluated. The FCT sample treated at 350 °C in H₂-atmosphere (FCT/H350) showed significant improvement in photodecomposition of 100 ppm of RB which completely disappeared within 40 min of the reaction. The apparent rate constant of FCT/H350 was 8.71 × 10⁻² min⁻¹, which is 4-folds faster than that of bare-TiO₂. Moreover, the FCT/H350 exhibited an initial hydrogen generation rate (HGR) of 1593 µmol·g⁻¹·h⁻¹. Spectroscopic and electrochemical measurements were conducted to investigate the possible photocatalytic mechanism and photogenerated charge carriers pathway. This study aims to develop a magnetically separable, high-performance, and bifunctional catalyst for photocatalytic applications.