TiO2 is one of the most important photocatalysts, but it is inefficient for visible light photocatalysis due to its large band gap. Herein, the unique core-shell structured TiO2 photocatalyst was synthesized by a one-step hydrogen treatment at temperature of 400-600 degrees C. The novel catalyst exhibited excellent performance for visible light photocatalytic dye degradation at room temperature. Even under weak visible light (40 mW cm(-2)) illumination, its degradation efficiency for methylene blue dye was 400% higher than that of pristine TiO2. Such a large enhancement can be attributed to the stable Ti3+ centers inside the core for visible light photocatalytic activity and the disordered shell for dye adsorption.