Multistage Optimizing Optical Limiting by Introducing Platinum Species in Metal-Porphyrinic Framework Thin Films

Designing multimechanistic composite materials to overcome the boundedness of individual optical limiting (OL) materials is extremely important but remains challenging. Herein, the Pt species decorated metal-porphyrinic framework thin film was first fabricated by impregnating the ZnTCPP(H₂) MOF thin film with the K₂PtCl₄ precursor and HCHO reduction approach and serves as an effective OL device. The resulting Pt NPs@ZnTCPP(Pt) thin film synergistically combines the nonlinear optical (NLO) properties of metallic/organic nanostructures and exhibits strong OL performance with a giant nonlinear absorption coefficient (6.32 × 10^-6 m/W) and low OL threshold (2.16 J·cm^-2) superior to that of the individual ZnTCPP(H₂) components and most reported OL materials due to the strong charge transfer between the porphyrinic groups and Pt species. Moreover, the form of Pt species in the metal-porphyrinic framework thin film can be effectively regulated and further optimized the OL performance by adjusting the concentration of precursors. Taken together, this work not only presents a new strategy to enhance OL performance by fabricating the multimechanistic composite films but also provides a novel and efficient film candidate for nonlinear OL applications.