S-scheme AgVO3-decorated BaSnO3 heterojunction for efficient photoreduction of Mercury (II) ions under visible light

Heavy metal waste has been slowly accumulating in water supplies due to the industry's current growth, posing a serious threat to the environment and all living things. In this paper, we describe an unpretentious hydrothermal technique for forming barium stannate nanocrystals (BSO), which are then modified with different doses (3–12 wt.%) of AgVO3 (AVO). The structural, optical, and photocatalytic features of the resulted photocatalysts were positively impacted by the AVO loading, according to characterization studies. The decrease of the bandgap of BSO from 2.94 to 2.39 eV and an improvement in absorbing visible light are both confirmed by the AVO decorating of just 9.0 wt%. Additionally, under visible light, the ability of the as-prepared photocatalysts to reduce Hg2+ ions were evaluated. The complete photoreduction of Hg2+ ions over the 9% AVO/BSO nanocomposite were achieved at a higher kinetic rate constant (0.057 min−1) compared to pristine BSO NPs after 45 min of illumination. After being used five runs to reduce Hg2+ during visible illumination, the AVO/BSO heterojunctions demonstrated significant stability and outstanding photocatalytic practicability. And then, the Hg2+ photoreduction reaction's mechanism was explained. This study illustrates how modified BSO photocatalysts can be used in water remediation processes.