3D-Printed Metal–Organic Framework-Derived Composites for Enhanced Photocatalytic Hydrogen Generation

Direct ink writing technique is used to 3D print Ti-metal–organic framework (MOF) NH₂-MIL-125 mixed with boehmite dispersal. Pt is also deposited onto 3D-printed monolith using atomic layer deposition (ALD) to offer additional catalytic sites. The Ti-MOF-derived powder sample and the pyrolyzed 3D-printed monolith samples are evaluated for photocatalytic H₂ evolution under UV–vis light. As a proof of concept, herein, it is demonstrated that 3D-printed MOF-derived monolith photocatalysts show five times higher H₂ evolution performance compared with TiO₂/C powder sample due to better interaction between 3D-printed photocatalysts and the incident light. The high surface area, the formation of hierarchical macro- to nanopores, and the optimizable shape/size of the 3D-printed catalyst maximize the exposure of catalytic active sites to incident photons and increase their photocatalytic H₂ evolution performance. In addition, the N-functionalized porous carbon from organic linker, and the uniformly distributed Pt/PtO_x species deposited by ALD, provide cocatalytic active sites for photocatalytic reaction and further enhance photocatalytic activity 30% of 3D-printed monoliths. This work on the 3D-printed MOF-derived free-standing monoliths for photocatalytic application provides a readily available approach to further fabricate a variety of 3D-printed MOF-based and derived materials for different energy and environment applications.