Nano Fe-BTC composites were successfully synthesized by hydrothermal treatment with an ultrasonic method. Samples were characterized by XRD, FTIR, BET, SEM, EDS, and XPS. SEM result showed nano Fe-BTC particles size of 10-30 nm. Nano Fe-BTC showed the high surface area (1258 m2/g) and pore volume (0.99 cm3/g). Fe-BTC nanocomposites were tested for the photocatalytic degradation of reactive dye (reactive yellow RY-145) in aqueous solution. Fe-BTC composites exhibited high photocatalytic activity. Thus, at the pH of 6.5 and the high initial concentration of 100 mg RY-145/L, removal efficiency reached the value of 98.13% after 60 min. of reaction. Moreover, nano Fe-BTC also showed high RY-145 removal efficiency after 3 catalytic regeneration. This contributes to the sustainable development and green chemistry.