Metal–organic framework mixed-matrix coatings on 3D printed devices

Strategies to incorporate porous coatings on 3D printed devices with intricate geometries are critical to expanding the scope of application of this type of manufacturing technique. Herein, the preparation of metal–organic framework (MOF)/polymer dispersions to be applied as coatings for 3D printed devices is described. As a proof of concept, submicrometric crystals of a zeolitic imidazolate framework (ZIF-67) were dispersed in a binary mixture comprising a polymer and an organic solvent. The resulting dispersion is dispensed through the structure of 3D printed devices, and after gentle heating for a short time, a homogeneous and robust MOF/polymer mixed-matrix coating (MMC) is formed on the effective area of the 3D printed device. The developed MOF–MMC procedure is simple, fast, and does not require specific instrumentation, or synthetic skills. The resulting MOF–MMC 3D printed devices were evaluated for the peroxymonosulfate activation to enhance the degradation of organic dyes in water. After a degradation time of 30 min using rhodamine B (5 mg L⁻¹) as a model dye, the MOF–MMC 3D printed devices showed excellent reusability and reproducibility, degrading an average of 97–98% of the rhodamine B after 10 consecutive degradation cycles comparing three different devices. Dye degradation was evaluated in stirred-tank and flow-through column formats, demonstrating that the developed MOF–MMC procedure is a versatile, safe and convenient way to implement micro/nanoparticulated materials for water pollutant degradation applications.