Nanocluster growth via "graft-onto": effects on geometric structures and optical properties.

Atomically precise engineering on the nanocluster surface remains highly desirable for the fundamental understanding of how surface structures of a nanocluster contribute to its overall properties. In this paper, the concept of "graft-onto" has been exploited to facilitate nanocluster growth on surface structures. Specifically, the Ag ₂ (DPPM)Cl ₂ complex is used for re-constructing the surface structure of Pt ₁ Ag ₂₈ (SR) ₁₈ (PPh ₃ ) ₄ ( Pt ₁ Ag ₂₈ , SR = 1-adamantanethiolate) and producing a size-growth nanocluster - Pt ₁ Ag ₃₁ (SR) ₁₆ (DPPM) ₃ Cl ₃ ( Pt ₁ Ag ₃₁ ). The grafting effect of Ag ₂ (DPPM)Cl ₂ induces both direct changes on the surface structure ( e.g. , size growth, structural transformation, and surface rotation) and indirect changes on the kernel structure (from a fcc configuration to an icosahedral configuration). Remarkable differences have been observed by comparing optical properties between Pt ₁ Ag ₂₈ and Pt ₁ Ag ₃₁ . Significantly, Pt ₁ Ag ₃₁ exhibits high photo-luminescent intensity with a quantum yield of 29.3%, which is six times that of the Pt ₁ Ag ₂₈ . Overall, this work presents a new approach ( i.e. , graft-onto) for the precise dictation of nanocluster surface structures at the atomic level.
(This journal is © The Royal Society of Chemistry 2020.)