How to enhance photocatalytic efficiency for tetracycline degradation in natural aquatic environments using oxygen-vacancy-modified BiOI/BiOBr Composites: coupling DFT simulations with experiments

Oxygen vacancies could be induced into the heterojunction structure of BiOI/BiOBr via high-temperature calcination. Light absorption, charge transfer efficiency, photocatalytic activity, and mechanism are all intimately connected to oxygen vacancies. Density-functional theory simulations demonstrate that surface oxygen vacancies adsorb oxygen to active sites, whereas bulk oxygen vacancies activate oxygen adsorbed to the surface to reactive radicals. Meanwhile, the addition of oxygen vacancies efficiently reduces the effects of background ions and pH on tetracycline breakdown in the real aquatic environment. The experimental results are consistent with the DFT calculations. This paper presents a straightforward approach for creating heterojunction surface and bulk-phase oxygen vacancies, as well as an understanding of the many roles that different types of oxygen vacancies play in the photocatalytic degradation process.