Structure of the Au23-xAgx(S-Adm)15 Nanocluster and Its Application for Photocatalytic Degradation of Organic Pollutants

Ligands play an important role in determining the atomic arrangement within the metal nanoclusters. Here, we report a new nanocluster [Au23-xAgx(S-Adm)(15)] protected by bulky adamantanethiol ligands which was obtained through a one-pot synthesis. The total structure of [Au23-xAgx(S-Adm)(15)] comprises an Au13-xAgx icosahedral core, three Au-3(SR)(4) units, and one AgS3 staple motif in contrast to the 15-atom bipyramidal core previously seen in [Au23-xAgx(SR)(16)]. UV/Vis spectroscopy indicates that the HOMO-LUMO gap of [Au23-xAgx(S-Adm)(15)] is 1.5 eV. DFT calculations reveal that [Au19Ag4(S-Adm)(15)] is the most stable structure among all structural possibilities. Benefitting from Ag doping, [Au23-xAgx(S-Adm)(15)] exhibits drastically improved photocatalytic activity for the degradation of rhodamine B (RhB) and phenol under visible-light irradiation compared to Au-23 nanoclusters.