3D Printing of Functional Mesoporous Silica Monoliths with Embedded Metal and MOF Components

The advent of 3D printing has transformed the field of manufacturing, offering unprecedented opportunities to create complex structures. Digital light processing (DLP)-based stereolithography has been widely adopted by material scientists, and DLP printers are now commonly available. However, despite its innovative nature, 3D printing remains limited in terms of material compatibility, which has largely been restricted to organic polymers and their composite derivatives. The direct printing of inorganic and functional structures remains challenging. To expand the potential of 3D printing to a broader spectrum of emerging materials, a new type of inks based on photo-cross-linkable nanoparticles is developed. Specifically, silica nanocages functionalized with methacrylate ligands enable the direct printing of mesoporous silica monoliths, eliminating the need for additional organic binders or calcination. Innovative functionalized inks are further developed by adding metal salts (Co, Ni, Cu, and Pd) into the silica inks allowing the selective positioning of different metallic zones along a monolith. In addition, a complementary strategy is presented for the in situ growth of microporous metal-organic frameworks (HKUST-1) within printed mesoporous silica monoliths. These fabrication strategies pave the way for designing hierarchical architectures suitable for a wide range of catalytic and environmental applications, including reactors for cascade reactions and CO₂ capture.