Atomically Engineered Trimetallic Nanoclusters Toward Enhanced Photoluminescence and Photoinitiation Activity

Precise doping is of vital significance for atomic engineering and the establishment of structure-property relationships in nanocluster (NC) chemistry. Herein, two novel trimetallic MAu₁₈Cd₃ (M = Pd/Pt) NCs that are derived from M-doped Au₂₅ templates of MAu₂₄ are reported, in which the central doping of M atom and the surface-motif doping of Cd atoms are concurrently achieved. Compared to the original templates, Cd-induced surface engineering enhances the rigidity of the structural framework and enlarges the HOMO-LUMO gaps of the MAu₁₈Cd₃, significantly improving photoluminescent efficiency by suppressing nonradiative relaxation. The critical role of the central M (Pd/Pt) dopant in photoluminescence, which regulates the rate of radiative decay of excited-state electrons, has also been substantiated. More notably, the doped case of PtAu₁₈Cd₃ exhibits excellent photoinitiation activity in 3D two-photon printing with a high resolution of ≈140 nm, which may be attributed to the prolonged excited state. Overall, this work provides a generalized routine for the precise synthesis of multi-metal NCs with concurrent enhancements in photoluminescence and photoinitiation activity, which is expected to stimulate further research for the design and preparation of multi-functional, multi-metal NCs.