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

Abstract

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 Ti-dopants 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 µmol 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.