Defect-driven photocatalysis in Bi4Ti3O12: Unveiling the role of oxygen vacancies toward dual function sustainable environmental detoxification and energy conversion

초록

Defect engineering has been recognized as a powerful strategy for tailoring the electronic structure of nanomaterials, representing a paradigm shift in nanoscience from passive defect tolerance to deliberate defect design. This study aims to elucidate how oxygen vacancies (OVs) influence the photocatalytic performance and structural properties of Bi4Ti3O12 (BTO). Advanced characterization techniques were employed to investigate formation of OVs, electronic structure, charge density distribution, charge migration and separation and molecular activation in BTO. Strategies for introducing OVs, such as dopant incorporation, chemical reduction, and thermal treatments, were systematically reviewed. The effects on band-gap modulation and charge-carrier dynamics were further examined, with particular emphasis on BTO-OV-based heterojunctions and metal-deposited systems. Oxygen vacancies effectively narrow the band gap and enhance charge separation, thereby improving photocatalytic activity. BTO-OVs systems demonstrate strong potential in environmental and energy applications, including pollutant degradation, CO2 reduction, and H2 evolution. This review highlights the critical role of precise defect control in optimizing photocatalytic efficiency and guides the rational design of sustainable, lightdriven catalytic systems.

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