Catalytically Active Light Printed Microstructures

Light-induced additive manufacturing (3D printing) has revolutionized manufacturing and its integration into the fabrication of catalysts holds key potential to enable facile access to optimized catalyst geometries and designs. Herein - for the first time - micro- and macro-sized photocatalytically active 3D printed objects are introduced via a dual-function photoresin using a ruthenium(II) complex containing monomer as both a photoinitiator for the 3D printing process and as the active photocatalyst within the printed structure. The approach leverages the spatial and temporal control afforded by light-induced 3D printing techniques during both one- and two-photon printing to precisely position the photocatalyst within intricate geometries using a pentaerythritol triacrylate (PETA) based resin. The successful incorporation of ruthenium(II) complexes is demonstrated via time-of-flight secondary-ion mass spectrometry (ToF-SIMS) into desired sections of 3D-printed objects. The one- and two-photon fabricated architectures show photocatalytic activity in the C─H arylation of activated aryl bromides. The potential of tailored catalytically active 3D objects is exemplified by one of the microscale designs. This design, utilizing only 1% of the volume of a macroscale structure fabricated from the same resin, achieved 75% of the photocatalytic performance.