First-principles study of Cu-doping and oxygen vacancy effects on TiO2 for water splitting

- Cu-doping and oxygen vacancies in TiO2 have been studied by DFT calculations.
- Both types of defects improve optical absorption in the visible region.
- Cu-doping and oxygen vacancies have a synergy effect on the electronic structure.
- Cu-doped oxygen deficient TiO2 could be a promising high-efficiency photocatalyst.