2, University of Tennessee, Knoxville, Knoxville, Tennessee, United States
3, University of Tennessee, Knoxville, Knoxville, Tennessee, United States
4, University of Tennessee, Knoxville, Knoxville, Tennessee, United States
Metal Organic Framework (MOF) structures represent an enormous potential for applications ranging from separation processes to catalysts in energy production and storage. Specifically, encapsulation of functional nanoparticles (NPs) within MOF structures can expand their implementation scope and enhance their functionalities. The versatility of such nanocomposite structures can be attributed to their porous networks, large available surface areas and single crystalline nature in addition to their facilitation of well-dispersed NPs with unobstructed surfaces under the confinement of porous MOFs that can promote catalytic activities. Although a large volume of work in recent years have focused on the synthesis of MOF and MOF/NP composites, a fast, reliable and facile methodology for the fabrication of MOF-confined functional NPs with controlled morphology and uniform spatial distributions is still elusive. Here we report a rapid, facile strategy utilizing our recently developed laser ablation synthesis in solution-galvanic replacement reaction (LASiS-GRR) technique for the first time for the synthesis of Platinum (Pt) NPs confined within two different structures: Zeolitic Imidazolate Framework-67 (ZIF-67) and Zeolitic Imidazolate Framework-8 (ZIF-8). Our results indicate that this technique allows us to achieve superior control on the tailored size, morphology and spatial distributions of NP/MOF porous composites tuning the high-energy physiochemical conditions emerging from liquid-confined, laser-induced plasma as well as the solution-phase reaction pathways driven by the GRR mechanisms. We show that the advantage of such confined nanocomposite structures is in its ability to achieve well-dispersed and spatially confined NPs after calcination treatments on suitable substrates that hinders NP aggregations during catalytic activities. To this end, preliminary results for post-calcined Pt/MOF composites have also shown promising catalytic activities towards Oxygen Reduction (ORR) and Oxygen Evolution Reactions (OER).