Ligand Modulation Triggers Metal Nanocluster NIR-II Photocatalysis

Owing to its high energy utilization and penetrability, near-infrared II (NIR-II) photocatalysis has emerged as a promising catalytic mode. A central challenge in this research area is solving the contradiction between near-infrared absorption and efficient energy transfer. Organic ligand-protected atomically precise metal nanoclusters with up-conversion properties are potential NIR-II photocatalysts, while constructing appropriate nanocluster structures for NIR-II photocatalysis is challenging. Here, we developed a ligand modulation strategy for transforming a triphenylphosphine-protected Au13Cd2 (Au13Cd2-TPP) to 1,1′-binaphthyl-2,2′-bisdiphenylphosphine-protected Au13Cd2 (Au13Cd2–BINAP). The resulting Au13Cd2–BINAP exhibits two types of up-conversion absorption capabilities, namely frequency up-conversion and two-photon absorption, which Au13Cd2-TPP does not have. Additionally, incorporation of BINAP on the surface of Au13Cd2 significantly improves the excited-state lifetime and photostability of this nanocluster, enabling highly efficient NIR-II photocatalysis of Au13Cd2–BINAP nanocluster.