Photosensitization Efficiency Modulation of Atomically Precise Silver Nanoclusters for Photoelectrocatalysis

Abstract

Atomically precise metal nanoclusters (NCs) have emerged as feasible alternatives to traditional photosensitizers in solar energy conversion due to the unique atomic stacking mode, quantum size effect, and abundant active sites. Despite the sporadic advancement in fabricating metal NC-based photosystems, most of which are predominantly centered on Au NCs, unleashing atomically precise silver nanoclusters as light-harvesting antennas has still been in the infant stage, with the charge transfer mechanism remaining elusive. Herein, we comprehensively demonstrate the photosensitization effect of Ag NCs in the photoelectrochemical (PEC) water-splitting reaction and strictly evaluate the correlation of photosensitization efficiency with atomic architecture. To these ends, tailor-made negatively charged l-glutathione (GSH)-capped Ag NCs [Ag x , Ag9(GSH)6, Ag16(GSH)9, Ag31(GSH)19] as building blocks are controllably deposited on the metal oxide (MOs = TiO2, WO3, Fe2O3) substrate by a facile self-assembly strategy. Benefiting from the highly efficient photosensitization effect of atomically precise Ag NCs, these self-assembled MOs/Ag NC heterostructured photoanodes with an elegant charge transfer interface demonstrate significantly enhanced photoelectrochemical water oxidation performances under visible-light irradiation on account of efficient charge transport from Ag NCs to the MO substrate, substantially prolonging the charge lifetime of Ag NCs. Our work would significantly inspire ongoing interest in unlocking the generic photosensitization capability of atomically precise metal NCs for solar energy conversion.

Atomically Precise Metal Nanocluster Photosystem: Electron Relay Boosts Photocatalytic Organic Transformation

“…Owing primarily to the strong binding affinity between the thiol group of GSH and Ag species, the monolayer of GSH molecules could be assembled on the Ag NC surface, which is referred to as thiolated Ag NCs . In this work, aggregation-induced emission (AIE)-type Ag 9 @(GSH) 6 NCs are obtained by condensing Ag­(I)-GSH complexes on the in situ-generated Ag(0) core . Considering that the Ag 9 @(GSH) 6 NC surface is wrapped by GSH ligands possessing abundant carboxyl species (−COO – ) (Figure S2a, b), it is thus negatively charged (Figure S1).…”

“…22 In this work, aggregation-induced emission (AIE)-type Ag 9 @(GSH) 6 NCs are obtained by condensing Ag(I)-GSH complexes on the in situ-generated Ag(0) core. 23 Considering that the Ag 9 @(GSH) 6 NC surface is wrapped by GSH ligands possessing abundant carboxyl species (−COO − ) (Figure S2a, b), it is thus negatively charged (Figure S1). Accordingly, negatively charged Ag 9 @GSH NCs can be drawn in by positively charged CdS@PAH via a strong electrostatic attractive force, giving rise to CdS@PAH@Ag 9 heterostructures.…”

Atomically Precise Metal Nanoclusters for Photocatalytic Water Splitting

“…To achieve highly efficient solar driven PEC H 2 production, the fundamental scientific question to be addressed is how to overcome the transport limitation of photon energy from the photoactive centers to the catalytic active sites on the surface. This question can be further divided into three parts: light absorption and charge carrier excitation; separation and transport of the charge carriers; surface catalytic reaction. − This Perspective briefly reviews the emerging works that use atomically precise metal NCs for water splitting and solar energy conversion. It should be noted that the metal NCs mentioned here are atomically precise, although NCs with ambiguous structural information have also been applied in water splitting. , Normally, they are prepared by wet chemistry methods in the presence of protecting ligands and have their structure solved. − Metal NCs that are prepared in gas phase and those without atomic precision are not in the scope of this perspective. − …”