Structure of the Au23-x Agx (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-x Agx (S-Adm)15 ] protected by bulky adamantanethiol ligands which was obtained through a one-pot synthesis. The total structure of [Au23-x Agx (S-Adm)15 ] comprises an Au13-x Agx icosahedral core, three Au3 (SR)4 units, and one AgS3 staple motif in contrast to the 15-atom bipyramidal core previously seen in [Au23-x Agx (SR)16 ]. UV/Vis spectroscopy indicates that the HOMO-LUMO gap of [Au23-x Agx (S-Adm)15 ] is 1.5 eV. DFT calculations reveal that [Au19 Ag4 (S-Adm)15 ] is the most stable structure among all structural possibilities. Benefitting from Ag doping, [Au23-x Agx (S-Adm)15 ] exhibits drastically improved photocatalytic activity for the degradation of rhodamine B (RhB) and phenol under visible-light irradiation compared to Au23 nanoclusters.