Continuously Adjustable Thickness of Bi₂MoO₆ Nanosheets Enhances Photocatalytic Oxidation

In this study, two-dimensional (2D) nanosheet photocatalysts of Bi₂MoO₆ with varying thicknesses were synthesized by adjusting the temperature during the hydrothermal reaction. The thinnest Bi₂MoO₆ nanosheet reached an approximate thickness of ∼4 nm, while the thickest nanosheet measured only ∼16 nm. The photocatalytic performance for Rhodamine B (RhB) degradation was found to be the most effective for the thinnest Bi₂MoO₆ nanosheet, displaying a degradation rate constant of 0.11 min^-1. This rate was 2.5 times higher than that observed for the ∼16 nm thick Bi₂MoO₆ photocatalyst. The enhanced performance of the thinner two-dimensional nanostructure can be attributed to improved separation and migration of photogenerated charges. Additionally, the study identified hydroxyl radicals (•OH) and superoxide radicals (•O₂^-) as crucial oxidative species, contributing to the efficient mineralization of RhB dye. This work highlights the controllable synthesis of 2D materials with varying thicknesses and their specific applications in photocatalytic oxidation.