Abstract: The core-shell structured nano-TiO₂ microspheres were successfully prepared by one-step solvothermal method with titanium tetrachloride as raw material, ammonium sulfate as dispersant, and urea as precursor. The structural parameters of TiO₂ microspheres (including core-shell size, grain size, specific surface area, pore size, etc.) were controlled by the solvothermal temperature. The photocatalytic degradation of gaseous benzene was investigated. The results show that the core and shell of microspheres gradually separates with the increase of solvothermal temperature, and the hollow structure become more obvious, and displays a secondary structure composed of nanoparticles below 20 nm. The specific surface area of the microspheres is up to 265.4 m²/g, the porosity is up to 0.247 8 cm³/g, the light absorption performance is higher than P25 TiO₂, and the edge of the light absorption band shows "blue shift". The core-shell structure microspheres exhibit adsorption synergistic photocatalytic degradation of benzene, especially the sample prepared at 180 ℃ has the highest photocatalytic activity, the excellent performance may ascribe to the sufficient scattering and absorption of light by the core-shell structure, its excellent crystallinity and high specific surface area.

Key words: TiO₂ microsphere, core-shell structure, solvothermal method, photocatalysis, gaseous benzene, degradation