Efficient Adsorption of Methylene Blue Using a Hierarchically Structured Metal-Organic Framework Derived from Layered Double Hydroxide.

The growing concerns about environmental pollution, particularly water pollution, are causing an increasing alarm in modern society. One promising approach to address this issue involves engineering existing materials to enhance their effectiveness. A one-step solvothermal reconstruction approach was used to build an eco-friendly two-dimensional (2D) AlNiZn-LDH/BDC MOF composite. The characterizations confirm the formation of a metal-organic framework (MOF) at the layered double hydroxide (LDH) surface. The resulting synthesized material, 2D AlNiZn-LDH/BDC MOF, demonstrated remarkable efficacy in decontaminating methylene blue (MB), a model cationic dye found in water systems. The removal performance of 2D AlNiZn-LDH/BDC MOF was significantly higher than that of pristine 2D AlNiZn-LDH. This improvement shows the potential to increase the adsorption capabilities of nanoporous LDH materials by incorporating organic ligands and integrating meso-/microporosity through MOF formation on their surfaces. Furthermore, their kinetic, isothermal, and thermodynamic studies elucidated the adsorption behavior of this composite material. The results of synthesized MOF showed excellent removal efficiency (92.27%) of 10 ppm of MB aqueous solution as compared to pristine LDH. Additionally, the as-synthesized adsorbent could be regenerated for six successive cycles. This method holds promise for the synthesis of novel and highly effective materials to combat water pollution, laying the groundwork for potential advancements in diverse applications.