Tuning atomically precise metal nanocluster mediated photoelectrocatalysis <i>via</i> a non-conjugated polymer

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Tunable charge transport over atomically precise metal nanoclusters is stimulated in layer-by-layer-assembled multilayered photoanodes for solar energy conversion.

Abstract

In recent years, atomically precise metal nanoclusters (NCs) have demonstrated fascinating applicability in solar energy conversion due to their unique atomic stacking arrangements, quantum size effect and abundant active sites. Nevertheless, ultra-short carrier lifetimes and poor stabilities impede the construction of robust metal-NC-based photosystems. Herein, positively charged poly(diallyl-dimethylammonium chloride) (PDDA) and tailor-made negatively charged l-glutathione (GSH)-capped Ag _x@GSH [Ag ₉(SG) ₆, Ag ₁₆(SG) ₉ and Ag ₃₁(SG) ₁₉] NCs are used as building blocks and alternately deposited on a one-dimensional wide-band-gap metal oxide (MO) substrate using a facile and general layer-by-layer (LbL) assembly strategy to design a highly efficient spatially directional charge transport pathway in multilayered photoanodes. The electrons photoexcited from the periodically stacked Ag _x@GSH [Ag ₉(SG) ₆, Ag ₁₆(SG) ₉ and Ag ₃₁(SG) ₁₉] NC layers concurrently and unidirectionally migrate to the MO substrate, while the ultrathin PDDA intermediate layer serves as an interfacial electron-withdrawing charge mediator to accelerate the transport of the carriers photoexcited over the neighboring Ag _x@GSH [Ag ₉(SG) ₆, Ag ₁₆(SG) ₉ and Ag ₃₁(SG) ₁₉] NC layers. Benefiting from the charge transfer enhancement, these LbL-assembled multilayered MO/(PDDA/Ag _x NCs) _n heterostructured photoanodes demonstrate significantly enhanced photoelectrochemical water oxidation performance under visible light irradiation due to the generation of unidirectional and spatially separated tandem charge transfer channels, which remarkably reduces the charge recombination and prolongs the carrier lifetime of the metal NCs. Moreover, we ascertain that this conceptual multilayered nanoarchitecture design and tandem charge transport are universal.

Related collections

Most cited references 51

Record: found
Abstract: found
Article: not found

Atomically Precise Colloidal Metal Nanoclusters and Nanoparticles: Fundamentals and Opportunities.

Rongchao Jin, Chenjie Zeng, Meng Zhou … (2016)

Colloidal nanoparticles are being intensely pursued in current nanoscience research. Nanochemists are often frustrated by the well-known fact that no two nanoparticles are the same, which precludes the deep understanding of many fundamental properties of colloidal nanoparticles in which the total structures (core plus surface) must be known. Therefore, controlling nanoparticles with atomic precision and solving their total structures have long been major dreams for nanochemists. Recently, these goals are partially fulfilled in the case of gold nanoparticles, at least in the ultrasmall size regime (1-3 nm in diameter, often called nanoclusters). This review summarizes the major progress in the field, including the principles that permit atomically precise synthesis, new types of atomic structures, and unique physical and chemical properties of atomically precise nanoparticles, as well as exciting opportunities for nanochemists to understand very fundamental science of colloidal nanoparticles (such as the stability, metal-ligand interfacial bonding, ligand assembly on particle surfaces, aesthetic structural patterns, periodicities, and emergence of the metallic state) and to develop a range of potential applications such as in catalysis, biomedicine, sensing, imaging, optics, and energy conversion. Although most of the research activity currently focuses on thiolate-protected gold nanoclusters, important progress has also been achieved in other ligand-protected gold, silver, and bimetal (or alloy) nanoclusters. All of these types of unique nanoparticles will bring unprecedented opportunities, not only in understanding the fundamental questions of nanoparticles but also in opening up new horizons for scientific studies of nanoparticles.

0 comments Cited 588 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Atomically Precise Clusters of Noble Metals: Emerging Link between Atoms and Nanoparticles.

Indranath Chakraborty, Thalappil Pradeep (2017)

Atomically precise pieces of matter of nanometer dimensions composed of noble metals are new categories of materials with many unusual properties. Over 100 molecules of this kind with formulas such as Au25(SR)18, Au38(SR)24, and Au102(SR)44 as well as Ag25(SR)18, Ag29(S2R)12, and Ag44(SR)30 (often with a few counterions to compensate charges) are known now. They can be made reproducibly with robust synthetic protocols, resulting in colored solutions, yielding powders or diffractable crystals. They are distinctly different from nanoparticles in their spectroscopic properties such as optical absorption and emission, showing well-defined features, just like molecules. They show isotopically resolved molecular ion peaks in mass spectra and provide diverse information when examined through multiple instrumental methods. Most important of these properties is luminescence, often in the visible-near-infrared window, useful in biological applications. Luminescence in the visible region, especially by clusters protected with proteins, with a large Stokes shift, has been used for various sensing applications, down to a few tens of molecules/ions, in air and water. Catalytic properties of clusters, especially oxidation of organic substrates, have been examined. Materials science of these systems presents numerous possibilities and is fast evolving. Computational insights have given reasons for their stability and unusual properties. The molecular nature of these materials is unequivocally manifested in a few recent studies such as intercluster reactions forming precise clusters. These systems manifest properties of the core, of the ligand shell, as well as that of the integrated system. They are better described as protected molecules or aspicules, where aspis means shield and cules refers to molecules, implying that they are "shielded molecules". In order to understand their diverse properties, a nomenclature has been introduced with which it is possible to draw their structures with positional labels on paper, with some training. Research in this area is captured here, based on the publications available up to December 2016.