A low-cost and simplistic approach for the synthesis of nanosized SO42-/TiO2 photocatalyst was successfully performed using Binh Dinh ilmenite ore and H2SO4 as titanium and sulfur sources, respectively. The experimental results indicate that the obtained material exists in the form of particles with a size of about 22 nm and has a specific surface area of about 49 m2 g-1. Compared with the TiO2 sample, the SO42-/TiO2 sample shows much higher photocatalytic degradation of rhodamine B (RhB) under the sunlight irradiation. In more details, the nanosized SO42-/TiO2 sample obtained is capable of completely decomposing RhB after 9 hours of irradiation by a 60 W LED lamp with a corresponding intensity of 9,500 Lux. However, when the SO42-/TiO2 is irradiated by the sunlight with the intensity of 65,000 Lux, it only takes 2 hours to completely decompose rhodamine B (RhB), facilitating the use of SO42-/TiO2 as a potential photocatalyst for the RhB photodegradation.