Creating and tailoring ultrathin two-dimensional uranyl-organic framework nanosheets for boosting photocatalytic oxidation reactions

Abstract

The fabrication of ultrathin MOFs nanosheets (just single- or few-layer) is highly desired but seriously restricted by the relatively strong interactions between layers in layered MOFs precursors. Herein, for the first time, we employ a proof-of-concept weak supramolecular-interactions strategy to construct ultrathin uranyl-organic framework nanosheets. Impressively, the thickness of the resulting nanosheets is extremely thin down to only 1 nm, just equal to two layers, and also shows high dependence on the stacking mode of 2D uranyl MOFs precursors, for example, two layers in the eclipsed stacking mode vs. eight layers in the staggered stacking mode. Most importantly, this would significantly tailor their optical and electronic properties. As a result, the ultrathin nanosheet samples (two layers) present significantly enhanced photocatalytic oxidation activity compared to their pristine counterpart (4.5 times) and another nanosheet sample (eight layers, 2.2-fold). This work may open up a gate toward ultrathin uranyl-organic nanosheet for advanced functions.