Precise design of dual active-site catalysts for synergistic catalytic therapy of tumors.

A proven and promising method to improve the catalytic performance of single-atom catalysts through the interaction between bimetallic atoms to change the active surface sites or adjust the catalytic sites of reactants is reported. In this work, we used an iron-platinum bimetallic reagent as the metal source to precisely synthesise covalent organic framework-derived diatomic catalysts (FePt-DAC/NC). Benefiting from the coordination between the two metal atoms, the presence of Pt single atoms can successfully regulate Fe-N activity.

Synthesizing Photoluminescent Au (SCH Ph- Bu) Nanoclusters with Structural Features by Using a Combined Method.

We present a method for atomically precise nanocluster synthesis. As an illustration, we introduced the reducing-ligand induction combined method and synthesized a novel nanocluster, which was determined to be Au (SCH Ph- Bu) with the same number of gold atoms as existing Au (SR) nanoclusters but different ligands (hetero-composition-homo-size). Compared with the latter, the former has distinct properties and structures.

Compression-Driven Internanocluster Reaction for Synthesis of Unconventional Gold Nanoclusters.

Can the active kernels in ultrasmall metal nanoparticles (nanoclusters, NCs) react with one another, or can the internanocluster reaction occur when they are in close enough proximity? To resolve this fundamental issue, we investigated the solid-state internanocluster reaction of the most studied gold NC Au (SR) (SR: thiolate). A novel NC was produced by increasing the pressure to 5 GPa, whose composition was determined to be Au (SC H Ph) by mass spectrometry and thermogravimetric analysis. As revealed by single-crystal X-ray crystallography, the structure, a bicuboid Au kernel and three pairs of interlocked trimetric staples, has not been reported and endows the NC with obvious photoluminescence.

Traceless Removal of Two Kernel Atoms in a Gold Nanocluster and Its Impact on Photoluminescence.

Removing or adding kernel atoms of metal nanoclusters (NCs) without leaving a trace is a substantial challenge because the kernel atoms are inside and covered by the outer staples. However, such kernel tuning is very important for improving the properties and acquiring an in-depth understanding of the kernel-property correlation. Photoluminescence (PL) is one of the most intriguing characteristics of metal NCs but has not been well understood until now.

Distance makes a difference in crystalline photoluminescence.

Crystallization-induced photoluminescence weakening was recently revealed in ultrasmall metal nanoparticles. However, the fundamentals of the phenomenon are not understood yet. By obtaining conformational isomer crystals of gold nanoclusters, we investigate crystallization-induced photoluminescence weakening and reveal that the shortening of interparticle distance decreases photoluminescence, which is further supported by high-pressure photoluminescence experiments.

A Dual Purpose Strategy to Endow Gold Nanoclusters with Both Catalysis Activity and Water Solubility.

Gold nanoclusters have attracted extensive interest for catalysis applications in recent years due to their ultrasmall sizes and well-defined compositions and structures. However, at least two challenges exist in this emerging field. First, the steric hindrance of the ligands inhibits the catalysis activity, and second, the mechanism underlying water-phase catalysis using gold nanoclusters is often ambiguous.

Alternating Array Stacking of Ag Au and Ag Au Nanoclusters.

An assembly strategy for metal nanoclusters using electrostatic interactions with weak interactions, such as C-H⋅⋅⋅π and π⋅⋅⋅π interactions in which cationic [Ag Au(2-EBT) (PPh ) ] and anionic [Ag Au(2-EBT) ] nanoclusters gather and assemble in an unusual alternating array stacking structure is presented. [Ag Au(2-EBT) (PPh ) ] [Ag Au(2-EBT) ] is a new compound type, a double nanocluster ion compound (DNIC). A single nanocluster ion compound (SNIC) [PPh ] [Ag Au(2-EBT) ] was also synthesized, having a k-vector-differential crystallographic arrangement.

Fcc versus Non-fcc Structural Isomerism of Gold Nanoparticles with Kernel Atom Packing Dependent Photoluminescence.

Structural isomerism allows the correlation between structures and properties to be investigated. Unfortunately, the structural isomers of metal nanoparticles are rare and genuine structural isomerism with distinctly different kernel atom packing (e.g.

Discovery, Mechanism, and Application of Antigalvanic Reaction.

Among many outstanding findings associated with the quantum size effect, one of the most exciting is the discovery of the antigalvanic reaction (AGR), which is the opposite of the classic galvanic reaction (GR) that has a history of nearly 240 years. The GR, named after Italian scientist Luigi Galvani, involves the spontaneous reduction of a noble-metal cation by a less noble metal in solution driven by the difference in electrochemical potentials. Classic galvanic reduction has been widely applied and has recently received particular interest in nanoscience and nanotechnology.

Kernel Homology in Gold Nanoclusters.

Homology is well known in organic chemistry; however, it has not yet been reported in nanochemistry. Herein, we introduce the concept of kernel homology to describe the phenomenon of metal nanoclusters sharing the same "functional group" in kernels with some similar properties. To illustrate this point, we synthesized two novel gold nanoclusters, Au (TBBT) and Au (TBBT) (TBBTH=4-tert-butylbenzenethiol), and solved their total structures by X-ray crystallography, which reveals that they have the same Au bi-icosahedron capped with a similar bottom cap (Au and Au , respectively) in the kernels.

Kernel Tuning and Nonuniform Influence on Optical and Electrochemical Gaps of Bimetal Nanoclusters.

Fine tuning nanoparticles with atomic precision is exciting and challenging and is critical for tuning the properties, understanding the structure-property correlation and determining the practical applications of nanoparticles. Some ultrasmall thiolated metal nanoparticles (metal nanoclusters) have been shown to be precisely doped, and even the protecting staple metal atom could be precisely reduced. However, the precise addition or reduction of the kernel atom while the other metal atoms in the nanocluster remain the same has not been successful until now, to the best of our knowledge.

Surface Single-Atom Tailoring of a Gold Nanoparticle.

Surface single-atom tailoring of a gold nanoparticle, that is, adding, removing, or replacing one surface atom on a structure-resolved nanoparticle in a controlled manner, is very exciting yet challenging and has not been hitherto achieved. Herein we report the first realization of the introduction of a single sulfur atom onto the surface of the structure-unraveled AuS(SCHPh) nanoparticle. Single-crystal X-ray crystallography reveals that the as-obtained nanoparticle consists of one Au kernel protected by one AuS(SCHPh) and one unprecedented AuS(SCHPh) motif with the introduced sulfur atom included as a tetrahedral-coordinated μ-S.

The reactivity of phenylethanethiolated gold nanoparticles with acetic acid.

We report the size-dependent reactivity of phenylethanethiolated gold nanoparticles with acetic acid. Employing this reactivity, we synthesize a novel nanocluster Au(PET) (PET: phenylethanethiolate), which is otherwise difficult to obtain and exhibits remarkably different photoluminescence and electrochemical properties compared with the well-known Au(PET) nanoclusters. And the reaction process between Au(PET) and acetic acid was probed by matrix-assisted laser desorption/ionization time of flight mass spectrometry.

The fourth crystallographic closest packing unveiled in the gold nanocluster crystal.

Metal nanoclusters have recently attracted extensive interest not only for fundamental scientific research, but also for practical applications. For fundamental scientific research, it is of major importance to explore the internal structure and crystallographic arrangement. Herein, we synthesize a gold nanocluster whose composition is determined to be AuS(SCHPh) by using electrospray ionization mass spectrometry and single crystal X-ray crystallography (SCXC).

Fluorescent Gold Nanoclusters with Interlocked Staples and a Fully Thiolate-Bound Kernel.

The structural features that render gold nanoclusters intrinsically fluorescent are currently not well understood. To address this issue, highly fluorescent gold nanoclusters have to be synthesized, and their structures must be determined. We herein report the synthesis of three fluorescent Au24 (SR)20 nanoclusters (R=C2 H4 Ph, CH2 Ph, or CH2 C6 H4 (t) Bu).

Synthesis of fluorescent phenylethanethiolated gold nanoclusters via pseudo-AGR method.

It is well known that the fluorescence of metal nanoclusters is strongly dependent of the protecting ligand and reports of phenylethanethiolated metal nanoclusters with distinct fluorescence are rare. Herein, a fluorescent phenylethanethiolated gold nanocluster is synthesized using an unexpected pseudo-AGR method (AGR: anti-galvanic reduction). The cluster is precisely determined to be Au24(SC2H4Ph)20 by isotope-resolved mass spectroscopy in tandem with thermogravimetric analysis (TGA).

Controlled synthesis of Au-Fe₃O₄ hybrid hollow spheres with excellent SERS activity and catalytic properties.

Au-Fe3O4 hybrid hollow spheres have been successfully synthesized by a one-pot process via the hydrothermal treatment of FeCl3, HAuCl4, citrate, urea, and polyacrylamide (PAM). The amount of Au nanoparticles located in the hybrid hollow spheres can be tuned by changing the molar ratio of Au/Fe precursors. A possible synthetic mechanism of the Au-Fe3O4 hybrid hollow spheres has been proposed.

A simple and highly efficient route to the synthesis of NaLnF4-Ag hybrid nanorice with excellent SERS performances.

This paper reports the synthesis of a new class of NaLnF(4)-Ag (Ln = Nd, Sm, Eu, Tb, Ho) hybrid nanorice and its application as a surface-enhanced Raman scattering (SERS) substrate in chemical analyses. Rice-shaped NaLnF(4) nanoparticles as templates are prepared by a modified hydrothermal method. Then, the NaLnF(4) nanorice particles are decorated with Ag nanoparticles by magnetron sputtering method to form NaLnF(4)-Ag hybrid nanostructures.

A facile strategy for obtaining fresh Ag as SERS active substrates.

A facile strategy has been reported to obtain on-line fresh Ag as surface-enhanced Raman scattering (SERS) active substrates by making AgCl nanoparticles exposed to the laser beam of Raman spectrometer. The composition and morphology of AgCl nanoparticles were characterized by X-ray diffraction (XRD), UV-visible (UV-vis) spectroscopy and scanning electron microscopy (SEM). The laser-driven evolvement and possible formation mechanism of cubic AgCl nanoparticles to Ag/AgCl composites were also investigated by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and high-resolution transmission electron microscopy (HRTEM).