Carbon nitride and titania nanoparticles prepared using porous silica templates and photocatalytic activity

This work examined the band structure and photocatalytic activity of carbon nitride and titania nanoparticles prepared using porous silica templates with pore sizes of approximately 1 and 3 nm. The carbon nitride and titania specimens prepared in this manner exhibited absorption edge blue shifts compared to bulk samples, due to expansion of their band gap resulting from quantum size effects. The photocatalytic activity of these materials during hydrogen production from water was assessed, and the activity of carbon nitride prepared in the 1 nm pores was higher than that of the material made using 3 nm pores as well as that of the bulk carbon nitride. These results suggest that the expansion of the HOMO-LUMO energy gap contributed to increasing the catalytic performance. In contrast, the titania materials did not generate hydrogen. X-ray absorption fine structure analyses demonstrated that the titania in the silica templates had a distorted structure, which may have decreased its photocatalytic activity.