In2S3/BiOI composites boost visible-light photocatalytic degradation of tetracycline hydrochloride.

In₂S₃/BiOI composites were synthesized at room temperature which significantly improved the photocatalytic degradation of tetracycline hydrochloride (TC) under visible light irradiation. Structure and morphology characterization techniques have been performed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction measurements (XRD) and X-ray photoelectron spectra (XPS). The separation ability of photogenerated carriers is enhanced due to the formation of heterojunctions of the composites. The best performance is obtained when the content of In₂S₃ is 7 wt%. Compared with In₂S₃ and BiOI alone, 7-In₂S₃/BiOI has the highest specific surface area and can provide more active sites. Based on the photo-electrochemical characterization and free radical tests, a photocatalytic mechanism of In₂S₃/BiOI composites in the presence of superoxide radicals (˙O₂⁻) and holes (h⁺) is reasonably proposed. [ABSTRACT FROM AUTHOR]