C‐Punkte zur Hand: Biokompatible lumineszierende Kohlenstoffnanopunkte mit geringer Toxizität und charakteristischer Photolumineszenz wurden synthetisiert. Diese „C‐Punkte“ könnten sich für vielfältige Anwendungen eignen, z. B. als Fälschungssicherung sowie zur Verschlüsselung oder Speicherung von Informationen.
C‐Punkte zur Hand: Biokompatible lumineszierende Kohlenstoffnanopunkte mit geringer Toxizität und charakteristischer Photolumineszenz wurden synthetisiert. Diese „C‐Punkte“ könnten sich für vielfältige Anwendungen eignen, z. B. als Fälschungssicherung sowie zur Verschlüsselung oder Speicherung von Informationen.
Five-fold-twinned PtCu nanoframes (NFs) with nanothorns protruding from their edges are synthesized by a facile one-pot method. Compared to commercial Pt/C catalyst, the obtained highly anisotropic five-fold-twinned PtCu NFs show enhanced electrocatalytic performance toward the oxygen reduction reaction and methanol oxidation reaction under alkaline conditions.
Crystal-phase engineering offers opportunities for the rational design and synthesis of noble metal nanomaterials with unusual crystal phases that normally do not exist in bulk materials. However, it remains a challenge to use these materials as seeds to construct heterometallic nanostructures with desired crystal phases and morphologies for promising applications such as catalysis. Here, we report a strategy for the synthesis of binary and ternary hybrid noble metal nanostructures. Our synthesized crystal-phase heterostructured 4H/fcc Au nanowires enable the epitaxial growth of Ru nanorods on the 4H phase and fcc-twin boundary in Au nanowires, resulting in hybrid Au-Ru nanowires. Moreover, the method can be extended to the epitaxial growth of Rh, Ru-Rh and Ru-Pt nanorods on the 4H/fcc Au nanowires to form unique hybrid nanowires. Importantly, the Au-Ru hybrid nanowires with tunable compositions exhibit excellent electrocatalytic performance towards the hydrogen evolution reaction in alkaline media.
High-yield preparation of ultrathin two-dimensional (2D) nanosheets is of great importance for the further exploration of their unique properties and promising applications. Herein, for the first time, the high-yield and scalable production of ultrathin 2D ternary chalcogenide nanosheets, including Ta2NiS5 and Ta2NiSe5, in solution is achieved by exfoliating their layered microflakes. The size of resulting Ta2NiS5 and Ta2NiS5 nanosheets ranges from tens of nanometers to few micrometers. Importantly, the production yield of single-layer Ta2NiS5 nanosheets is very high, ca. 86%. As a proof-of-concept application, the single-layer Ta2NiS5 is used as a novel fluorescence sensing platform for the detection of DNA with excellent selectivity and high sensitivity (with detection limit of 50 pM). These solution-processable, high-yield, large-amount ternary chalcogenide nanosheets may also have potential applications in electrocatalysis, supercapacitors, and electronic devices.
A photocatalytic strategy has been developed to synthesize colloidal Ag-TiO2 nanorod composites in which each TiO2 nanorod contains a single Ag nanoparticle on its surface. In this rational synthesis, photoexcitation of TiO2 nanorods under UV illumination produces electrons that reduce Ag(I) precursor and deposit multiple small Ag nanoparticles on the surface of TiO2 nanorods. Prolonged UV irradiation induces an interesting ripening process, which dissolves the smaller nanoparticles by photogenerated oxidative species and then redeposits Ag onto one larger and more stable particle attached to each TiO2 nanorod through the reduction of photoexcited electrons. The size of the Ag nanoparticles can be precisely controlled by varying the irradiation time and the amount of alcohol additive. The Ag-TiO2 nanorod composites were used as electron transport layers in the fabrication of organic solar cells and showed notable enhancement in power conversion efficiency (6.92%) than pure TiO2 nanorods (5.81%), as well as higher external quantum efficiency due to improved charge separation and transfer by the presence of Ag nanoparticles.
2D layered nanomaterials as photocatalysts have attracted much attention in the field of solar hydrogen production due to their unique electronic structure and abundant active sites. Nevertheless, the rational design and interfacial regulation of 2D Z‐scheme heterojunction are still challenging. Herein, an ultrathin 2D ZnIn2S4/g‐C3N4 Z‐scheme heterojunction is precisely constructed via in‐situ growth of ZnIn2S4 on the g‐C3N4. By carefully regulating the interface structure in heterojunction, the hydrogen evolution performance can be greatly improved. The optimized photocatalyst exhibits a remarkable photocatalytic activity without Pt as cocatalyst, which is primarily ascribed to the synergistic effect of abundant active sites, enhanced photoresponse, and valid interfacial charge transfer channels. Meanwhile, the spectroscopic analyses and density functional theory (DFT) calculation results comprehensively prove that the promoted interfacial charge separation in 2D Z‐scheme heterojunction is another key factor for the enhanced photocatalytic performance. This work offers a new avenue for the rational design of ultrathin Z‐scheme heterojunction photocatalysts with improved photocatalytic performance through interfacial engineering.
Heterostructures consisting of distinct components have attracted considerable attention due to their unique properties and promising applications in catalysis enabled by the synergistic effect among different components. [1][2][3][4][5] Since phase engineering of nanomaterials (PEN) provides various strategies to rationally design and synthesize nanomaterials with novel crystal phases, [6] the delicate modu lation of crystal phases of each component in heterostructures with diverse morpho logies becomes possible, which is of great importance to realize tunable physical and chemical properties and enhanced perfor mances. In addition to controlling their compositions, morphologies, architec tures, facets, sizes, and dimensionalities, tremendous efforts have been devoted to constructing heterostructures con sisting of different phases during recent years. For example, highly luminescent CdSe/CdS heterostructure with tetrapod Phase engineering of nanomaterials (PEN) offers a promising route to rationally tune the physicochemical properties of nanomaterials and further enhance their performance in various applications. However, it remains a great challenge to construct well-defined crystalline@amorphous core-shell heterostructured nanomaterials with the same chemical components. Herein, the synthesis of binary (Pd-P) crystalline@amorphous heterostructured nanoplates using Cu 3−χ P nanoplates as templates, via cation exchange, is reported. The obtained nanoplate possesses a crystalline core and an amorphous shell with the same elemental components, referred to as c-Pd-P@a-Pd-P. Moreover, the obtained c-Pd-P@a-Pd-P nanoplates can serve as templates to be further alloyed with Ni, forming ternary (Pd-Ni-P) crystalline@amorphous heterostructured nanoplates, referred to as c-Pd-Ni-P@a-Pd-Ni-P. The atomic content of Ni in the c-Pd-Ni-P@a-Pd-Ni-P nanoplates can be tuned in the range from 9.47 to 38.61 at%. When used as a catalyst, the c-Pd-Ni-P@a-Pd-Ni-P nanoplates with 9.47 at% Ni exhibit excellent electrocatalytic activity toward ethanol oxidation, showing a high mass current density up to 3.05 A mg Pd −1 , which is 4.5 times that of the commercial Pd/C catalyst (0.68 A mg Pd −1 ).
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