Jason

Ag nanoparticles (NPs) have gained great attention owing to their interesting plasmonic properties and efficient catalysis under visible-light irradiation. In this study, an Ag-based plasmonic catalyst supported on mesoporous silica with isolated and tetrahedrally coordinated single-site Ti-oxide moieties, namely, Ag/Ti-SBA-15, was designed with the purpose of utilizing the broad spectral range of solar energy. The Ti-SBA-15 support allows the deposition of small Ag NPs with a narrow size distribution. The chemical structure, morphology, and optical properties of the prepared catalyst were characterized by techniques such as UV/Vis, FT extended X-ray absorption fine structure, and X-ray photoelectron spectroscopy, field-emission SEM, TEM, and N₂ physisorption studies. The catalytic activity of Ag/Ti-SBA-15 in hydrogen production from ammonia borane by hydrolysis was significantly enhanced in comparison with Ag/SBA-15 without Ti-oxide moieties and Ag/TiO₂/SBA-15 involving agglomerated TiO₂, both in the dark and under light irradiation. Improved electron transfer under light irradiation caused by the creation of heterojunctions between Ag NPs and Ti-oxide moieties explains the results obtained in the present study.

Full-spectrum photocatalyst: A plasmonic Ag nanoparticle (NP) catalyst supported on mesoporous silica with isolated and tetrahedrally coordinated single-site Ti-oxide moieties, denoted as Ag/Ti-SBA-15, was designed to utilize the full spectral range of solar energy. The catalytic activity of Ag/Ti-SBA-15 in hydrogen production from ammonia borane by hydrolysis was significantly enhanced in comparison with Ag/SBA-15 without Ti-oxide moieties and Ag/TiO₂/SBA-15 involving agglomerated TiO₂, owing to the creation of heterojunctions between Ag NPs and Ti-oxide moieties (see figure).

The shape-controlled synthesis of metal nanoclusters (NCs) with precise atomic arrangement is crucial for tailoring the properties. In this work, we successfully control the shape of alloy NCs by altering the dopants in the alloying processes. The shape of the spherical [Pt₁Ag₂₄(SPhMe₂)₁₈] NC is maintained when [Au^ISR] is used as dopant. By contrast, the shape of Pt₁Ag₂₄ is changed to be rodlike by alloying with [Au^I(PPh₃)Br]. The structures of the trimetallic NCs were determined by X-ray crystallography and further confirmed by both DFT and far-IR measurements. The shape-preserved [Pt₁Au_6.4Ag_17.6(SPhMe₂)₁₈] NC is in a tristratified arrangement—[Pt(center)@Au/Ag(shell)@Ag(exterior)]—and is indeed the first X-ray crystal structure of thiolated trimetallic NCs. On the other hand, the resulting rodlike NC ([Pt₂Au₁₀Ag₁₃(PPh₃)₁₀Br₇]) exhibits a high quantum yield (QY=14.7 %), which is in striking contrast to the weakly luminescent Pt₁Ag₂₄ (QY=0.1 %, about 150-fold enhancement). In addition, the thermal stabilities of both trimetallic products are remarkably improved. This study presents a controllable strategy for synthesis of alloy NCs with different shapes (by alloying heteroatom complexes coordinated by different ligands), and may stimulate future work for a deeper understanding of the morphology (shape)–property correlation in NCs.

Shape-controlled synthesis of alloy metal nanoclusters (NCs) is achieved with atomic precision for the first time. The spherical [Pt₁Ag₂₄(SR)₁₈] was doped with [Au^ISR] or [Au^I(PPh₃)Br], resulting in spherical or rodlike trimetallic products, respectively. The spherical [Pt₁Au_6.4Ag_17.6(SPhMe₂)₁₈] NC represents the first X-ray crystal structure of a thiolated trimetallic NCs. The rodlike trimetallic [Pt₂Au₁₀Ag₁₃(PPh₃)₁₀Br₇] exhibits strong emission with a quantum yield of 14.7 %.

Mg batteries have potential advantages in terms of safety, cost, and reliability over existing battery technologies, but their practical implementations are hindered by the lack of amenable high-voltage cathode materials. The development of cathode materials is complicated by limited understandings of the unique divalent Mg²⁺ ion electrochemistry and the interaction/transportation of Mg²⁺ ions with host materials. Here, it is shown that highly dispersed vanadium oxide (V₂O₅) nanoclusters supported on porous carbon frameworks are able to react with Mg²⁺ ions reversibly in electrolytes that are compatible with Mg metal, and exhibit high capacities and good reaction kinetics. They are able to deliver initial capacities exceeding 300 mAh g⁻¹ at 40 mA g⁻¹ in the voltage window of 0.5 to 2.8 V. The combined electron microscope, spectroscopy, and electrochemistry characterizations suggest a surface-controlled pseudocapacitive electrochemical reaction, and may be best described as a molecular energy storage mechanism. This work can provide a new approach of using the molecular mechanism for pseudocapacitive storage of Mg²⁺ for Mg batteries cathode materials.

A new molecular storage approach with supported V₂O₅ nanoclusters is described for developing Mg batteries cathode materials. The highly dispersed V₂O₅ nanoclusters are able to react with Mg²⁺ ions reversibly in Mg battery electrolytes, and delivered initial capacities exceed 300 mAh g⁻¹. The electrochemical reaction has surface limited pseudocapacitive characteristics with outstanding kinetics.

Herein, to mimic complex natural system, polyelectrolyte multilayer (PEM)-coated mesoporous silica nanoreactors were used to compartmentalize two different artificial enzymes. PEMs coated on the surface of mesoporous silica could serve as a permeable membrane to control the flow of molecules. When assembling hemin on the surface of mesoporous silica, the hemin-based mesoporous silica system possessed remarkable peroxidase-like activity, especially at physiological pH, and could be recycled more easily than traditional graphene–hemin nanocompounds. The hope is that these new findings may pave the way for exploring novel nanoreactors to achieve compartmentalization of nanozymes and applying artificial cascade catalytic systems to mimic cell organelles or important biochemical transformations

Dividing lines: Polyelectrolyte multilayer (PEM)-coated mesoporous silica nanoreactors were constructed to compartmentalize two different artificial enzymes to mimic a complex natural system (see figure). The design might pave the way for exploring novel nanoreactors to achieve compartmentalization of nanozymes and the application of artificial cascade catalytic systems to mimic cell organelles or important biochemical transformations.

A seeded watermelon-like mesoporous nanostructure (mSiO₂@CdTe@SiO₂, mSQS) composed of a novel dendritic mesoporous silica core, fluorescent CdTe quantum dots (QDs), and a protective solid silica shell is successfully fabricated by loading QDs into dendritic mesoporous silica nanoparticles through electrostatic interaction, and then coating with a solid silica shell by the modified Stöber method. The shell thickness of mSQS can be tuned from 0 to 32 nm as desired by controlling the reaction parameters, including the amount of silica precursor, tetraethyl orthosilicate, that is introduced, the solvent ratio (H₂O:ethanol), and the amount of catalyst (NH₃⋅H₂O). These fluorescent mSiO₂@QDs@SiO₂ nanoparticles possess excellent stability and thickness-dependent cytotoxicity, and are successfully applied to bioimaging.

A seeded watermelon-like fluorescent mesoporous nanostructure (mSiO₂@CdTe@SiO₂) composed of a novel dendritic mesoporous silica core, fluorescent CdTe quantum dots, and a protective solid silica shell is successfully fabricated and applied to in vitro and in vivo bioimaging.