Quasi-2D MIL-100 (Fe) synthesis via benzene-1,3,5-tricarboxylic acid self-assembly: organic dye adsorption at room temperature with dramatically enhanced kinetics.

Amid increasing environmental pollution, two-dimensional materials have played pivotal roles in environmental remediation. However, two-dimensional metal-organic frameworks (2D-MOFs) have yet to be thoroughly explored. This study introduces a novel approach to synthesize 2D-MOFs, particularly focusing on MIL-100-(Fe), for the adsorption of emerging organic dyes. By harnessing the self-assembly of benzene-1,3,5-tricarboxylic acid (BTC), we formed thin solid interfaces of BTC as building blocks to control the growth of MIL-100-(Fe). This resulted in quasi-2D structures that showed over a 35% increase in adsorption capacity and a 5.5-fold increase in the adsorption kinetics of Rhodamine B removal compared to their 3D counterparts. This new method overcomes traditional synthesis limitations, offering a replicable and high-yield procedure for 2D-MOF synthesis. Compared to its three-dimensional counterpart (3D MIL-100 Fe), the prepared adsorbent exhibited remarkably higher efficacy in the adsorption of Rhodamine B, with high structural stability and recyclability. The prepared adsorbent shows over 99% adsorption within 90 minutes for initial dye concentrations of 1-40 mg L-1via the Langmuir adsorption mechanism and pseudo-second-order kinetics. Our research pioneers a method for the synthesis of quasi 2D-MIL-100-(Fe), laying the groundwork for fabricating other 2D-MOF structures, particularly those based on carboxylic acids.