Green and Large-Scale Preparation of MOF-303 via Ammonia and Steam-Assisted Conversion

Metal–organic frameworks (MOFs) exhibit significant practical application potential in various fields. However, their widespread application is often hindered by high cost and complicated synthesis procedures, such as the typical water-harvesting material MOF-303. Therefore, developing green, efficient, and cost-effective synthesis methods is essential to advance the application of such materials. In this work, we present a novel, efficient, and environmentally friendly synthesis method for MOF-303, achieved through ammonia and steam-assisted conversion. The resulting material exhibits excellent structural properties, including a high BET surface area of 1016 m²/g, making it well-suited for water adsorption. Powder X-ray diffraction confirms high crystallinity, and scanning electron microscopy reveals uniform rod-like crystals (1–3 μm). Importantly, the product exhibits a high water adsorption capacity of 0.43 g/g, comparable to that of conventionally synthesized MOF-303. This approach not only facilitates the solid-state growth of the MOFs but also eliminates waste liquid generation, significantly reducing the cost of wastewater treatment. The process is simple, easily controllable, and yields up to 91%. The cost of raw materials is significantly lower compared to the solvothermal synthesis. Furthermore, we have scaled up the synthesis using a laboratory-designed steam-assisted equipment, achieving a production capacity of MOF-303 at the hundred-gram level, marking an important step toward the industrial application of such materials.