Nanoporous carbon doped ceria bismuth oxide solid solution for photocatalytic water splitting

A series of carbon-doped solid solutions of ceria bismuth oxide (CBO) were prepared by a solid solution method. Highly porous solid solutions crystallized in a fluorite phase and C-doped samples exhibited an enhanced band-gap and reduced lattice cell constants. Their photocatalytic activity was observed in terms of H2 and O2 production via water splitting. The maximum hydrogen production was observed for a 6% C-doped solid solution in methanolic solution, i.e. 5413.10 mmol H2 g−1 h−1 under 300 W Xe light irradiation. The 6% C-doped solid solution released maximum O2 (193.80 μmol O2 h−1 g−1) and H2 (323.00 μmol H2 h−1 g−1) from pure water under exposure to real sunlight due to the highly ordered atomic arrangement, high porosity, high crystallinity, low oxygen vacancies, and high OH-group concentration in the lattice.