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

Abstract

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.