Heterogeneous photocatalysis: How doping with nitrogen can improve the performance of semiconductor nanoparticles under visible light irradiation

This chapter starts with an introduction to photocatalysts active under visible light. Then, the different doping modes for TiO2 are discussed. For its importance, nitrogen-doped TiO2 is described in great detail: in particular the synthesis of nitrogen-doped TiO2 was reported, focusing on the optimization of nitrogen-doped TiO2 photocatalytic activity using ammonia as nitrogen source. Finally, some applications of nitrogen-doped TiO2 in environmental remediation are presented, discussing the characteristic of structured supported photocatalysts, and briefly the photocatalytic performances when nitrogen-doped TiO2 is supported on glass spheres or on phosphors, luminescent materials able to convert light energy into photons of different energy. Nitrogen-doped TiO2 coupled with up-conversion phosphors and nitrogen-doped TiO2 coupled with down-conversion phosphors preparation and behaviors are summarized.