Oxygen Vacancies Modified Bi4O5I2 for Sensitive and Stable Photoelectrochemical‐Type Photodetection

Abstract Bismuth oxyiodides, like BiOI, Bi 4 O 5 I 2 and Bi 5 O 7 I, are widely recognized as a kind of famous photocatalyst. However, there are only a few studies on the photoelectrochemical (PEC) applications of bismuth oxyiodides, due to the poor photoresponse and stability in aqueous medium. In this study, enhancing the PEC performance of Bi 4 O 5 I 2 by introducing oxygen vacancies is attempted through a simple photo‐assisted method. Enhancement of the PEC performance of Bi 4 O 5 I 2 is investigated from the perspective of transport of photogenerated carriers. Benefiting from the promising PEC performance, the as‐constructed photodetector exhibits high sensitivity and stability. This work presents a simple route to enhance the PEC performance of bismuth‐mixed anion compounds, which can be beneficial for the design of high‐performance PEC‐type devices toward energy conversion and photodetection.