Photovoltaic Properties of Glutathione‐Protected Gold Clusters Adsorbed on TiO₂ Electrodes

Abstract

Glutathione‐protected Au25 as well as Aun (n = 15, 18, 22, 29, 33, 39) clusters adsorbed on TiO2 electrodes exhibit anodic photocurrents and negative shifts of photopotential in response to visible and/or near‐infrared light (400 < λ < 900 nm) on the basis of HOMO−LUMO and similar transitions, indicating that the electrodes are applicable to the conversion of light to electricity (see figure).

Ag7Au6: A 13‐Atom Alloy Quantum Cluster

“…1 H NMR of the cluster is similar to Ag 7,8 [10d] and Ag 9 [10h] clusters protected with MSA, but extent of chemical shift and line broadening are different.…”

“…The various stages of synthesis are shown in Figure 1. First step is the synthesis of polydisperse Ag@H 2 MSA nanoparticles followed by the synthesis of Ag 7,8 clusters by interfacial etching in the second step, as reported previously.…”

“…[2] Unusually intense luminescence and chemical reactivity of molecular clusters or quantum clusters (QCs) of noble metals, for example gold [3a-e,h] have attracted intense interest in areas such as nanophotonics, [4] bioimaging, [5] catalysis, [6] and others. [7] In the past several years, some of these clusters have been characterized thoroughly, both theoretically [8] and experimentally. [9] Several reports of various core sizes of silver clusters are also known.…”

“…Photographs of Ag 7,8 clusters and the alloy QC product after synthesis are shown in Figure 1. During the reaction, the solution becomes turbid and the color changes from reddish brown to orange, indicating the completion of the reaction.…”

“…[10d] Addition of an appropriate amount of 10 mm HAuCl 4 to the as-synthesized Ag 7,8 cluster in the third step yields the alloy cluster (for details see the Experimental Section). Photographs of Ag 7,8 clusters and the alloy QC product after synthesis are shown in Figure 1.…”