Sustainable and Cost-Effective Synthesis of Single-Layered 2D MIL-53(Al) Nanosheets for Efficient H₂S Capture

Hydrogen sulfide (H2S) poses negative effects on the realm of energy storage and conversion and human health owing to its corrosivity, catalyst poisoning, and toxicity. Hence, removing H2S from gas streams plays a crucial role in sections of gas-derived energy production and human life. Metal–organic frameworks (MOFs) have been extensively studied for H2S adsorption, thanks to their large surface area and tunable structure. This work presents a sustainable and cost-effective synthesis of single-layered two-dimensional (2D) MIL-53(Al) nanosheets with excellent ability for H2S adsorption. The 2D MIL-53(Al) is synthesized by an organic solvent-free protocol using plastic waste as a precursor source. Synthetic conditions are optimized to obtain a high-yield synthesis process and a material with tunable properties. The MIL-53(Al) nanosheet (thickness of 6.7 Å) with a single-layered structure is confirmed by scanning transmission electron microscopy and atomic force microscopy, which has never been reported yet. The material possesses a large surface area of 1112 m2·g–1 and good chemical and thermal stability. Regarding H2S adsorption, the 2D MIL-53(Al) exhibits a H2S capacity of 556 mg·g–1 under ambient conditions, and its potential regenerability is proven. These performances arise from facile exposure of H2S molecules to adsorptive sites in the 2D framework and reversible adsorption of the material toward H2S. This study opens a pathway for designing 2D MOFs in the field of H2S adsorption and provides a well-designed 2D MOF for further research strategies.