BiFeO3 bandgap engineering by dopants and defects control for efficient photocatalytic water oxidation

Tuning the electronic structure of a semiconductor via defects engineering is an effective strategy to modulate its band structure and charge carrier transport for superior photocatalytic properties. Herein, we report visible-light driven photocatalytic water oxidation on BiFeO3 nanoplates with Ti-dopants and oxygen vacancies, synthesized via facile hydrothermal method followed by thermal treatment in H2 atmosphere. The gradual increase of Tidopants progressively changes BiFeO3 morphology from rectangular cuboids to nanoplates. The introduction of Ti-dopants and oxygen vacancies tuned the band-gap of BiFeO3, enhanced visible light absorption, improved photogenerated charge-carrier dynamics, and higher driving force for O2 evolution to demonstrate excellent O2 evolution at a rate of 274 mu mol h-1 g-1 which is 2.6 times higher compared to pristine BiFeO3. Furthermore, threefold higher photocurrent density and superior surface photovoltage (SPV) results confirm improved charge carrier dynamics in BiFeO3 with Ti- dopants and oxygen vacancies, which make BiFeO3-based nanoplates promising material for photocatalytic applications.