Preparation and photocatalytic activity of nitrogen-doped TiO2 hollow nanospheres

TiO₂ hollow nanospheres were prepared using silicon oxide as a template. N-doped titanium oxide hollow spheres, TiO_2−xN_x were synthesized by reacting TiO₂ hollow spheres with thiourea at 500 °C. XRD and XPS data showed that oxygen was successfully substituted by nitrogen through the nitrogen-doping reaction, and finally N-doped TiO₂ hollow spheres were formed. The N-doped TiO₂ hollow spheres showed new absorption shoulder in visible light region so that they were expected to exhibit photocatalytic activity in the visible light. The photocatalytic activity of N-doped TiO₂ hollow spheres under visible light was similar to that of normal spherical TiO_2−xN_x in spite of the structural difference.