In-situ construction of S-scheme Bi4O5I2/BiOI heterojunctions with enriched oxygen vacancies and enhanced photocatalytic properties towards destruction of rhodamine B and tetracycline

Herein, novel S-scheme Bi4O5I2/BiOI heterojunctions were in-situ obtained through a hydrothermal method and post-roasting of BiOI prepared with the assistance of coconut shell. Bi4O5I2/BiOI photocatalytic materials was investigated by a series of characterization techniques. Abundant oxygen vacancies (OVs) were generated during the roasting process, proven by X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) results. The existence coconut shell in the preparation process can effectively enhance the separation efficiency of carriers of the samples fabricated. Photocatalytic activity of Bi4O5I2/BiOI toward destruction of rhodamine B (RhB) and tetracycline (TC) is 5.5 and 4.5 times of that of the blank BiOI, separately, and h+ plays a major role in the destruction reaction. This demonstration suggests that in-situ preparation of S-scheme heterojunctions by roasting of BiOI prepared with the assistance of coconut shell provides an effective path for preparation of highly efficient BiOI-based catalysts.