Fabrication of amorphous metal-organic framework in deep eutectic solvent for boosted organophosphorus pesticide adsorption

Herein, we describe a new and sustainable strategy of directly constructing the amorphous metal-organic framework (MOF) through the use of deep eutectic solvent (DES) for the highly effective and efficient adsorption of organophosphorus pesticide from contaminated water . The as-obtained products possessed nanosize morphology (as small as 40 nm), hierarchical pores ranging from 1.16 to 12.3 nm, high porosity up to 0.5954 cm 3 g −1 , and abundant unsaturated metal centers. The presence of structural disorder increased the number of active sites and promoted the diffusion of target molecules, leading to enhance host-guest interactions. These properties were beneficial for the application of the material in the enrichment adsorption of profenofos . The amorphous UiO-66 with the highest content of defect disorder (4.408) displayed a remarkably high affinity toward profenofos, resulting in an exceptional adsorbate uptake capacity over 1300 mg·g −1 . This is a three-fold enhancement compared to its crystalline counterpart. And its performance surpassed that of most previously reported absorbents. Additionally, the adsorption behavior and mechanism of amorphous UiO-66 toward profenofos were elucidated by high-revolution X-ray photoelectron spectroscopy (XPS) and various models. The results revealed a multi-layer heterogeneous adsorption, involving multiple sorption process. The profenofos adsorption mechanisms over amorphous UiO-66 mainly rely on hydrogen bonding, Zr-O-P bonds, and P-Zr bonds. Moreover, the amorphous UiO-66 exhibited outstanding regeneration and reusability characteristics, making it a stable and promising adsorbent for water remediation . Its efficient and rapid removal of pollutants holds great potential for practical applications, while also providing guidelines for the design and optimization of next-generation sorbent .