Construction of oxygen vacancy modified Bi/BiOI nanocomposite with improved photocatalytic activity for microcystin-LR degradation

Herein, a series of Bi/BiOI nanocomposites with oxygen vacancy modification have been prepared by the hydrogenated method. The Bi metal and oxygen vacancy were generated after annealing at high temperature concurrently. The obtained composite Bi/BiOI nanocomposite (label as x-BiOI, x means different annealing temperature) was used as a model photocatalyst to research the leading effects of oxygen vacancy and surface plasmon resonance (SPR) effect in microcystin-LR (MC-LR) photodegradation. As one of the most dangerous microcystins, the removal of MC-LR is urgent and meaningful. Moreover, based on the MC-LR photodegradation results, the photocatalytic activity of all oxygen vacancy modified Bi/BiOI nanocomposites was better than that of pristine BiOI. Meanwhile, the 500-BiOI photocatalysis shows the optimal photocatalysis performance. In detail, the degradation rate constant of 500-BiOI (0.56196 h⁻¹) is around five times higher than that of pristine BiOI (0.1047 h⁻¹). The microcystin toxin of intermediate was also analyzed systematically. The probable mechanism of the obtained sample was proposed for better understanding the MC-LR photodegradation process. This work provides a critical reference in water pollution treatment.