A hybrid design of Ag-decorated ZnO on layered nanomaterials (MgAC) with photocatalytic and antibacterial dual-functional abilities.

In this work, Ag@ZnO and Ag@ZnO/MgAC photocatalysts were synthesized using a simple two-step electrochemical method by the addition of magnesium aminoclay (MgAC) as a great stabilizer and a Lewis base, which could donate electrons for reduction of Ag+ and Zn2+ ions, facilitating uniform formation as well as effective inhibition of aggregation of Ag@ZnO nanoparticles (NPs) on the MgAC matrix. Ag@ZnO and Ag@ZnO/MgAC were investigated for photocatalytic degradation of MB and their antibacterial efficiencies. Ag@ZnO/MgAC showed excellent photocatalytic MB degradation with a performance of 98.56% after 80 min of visible-light irradiation and good antibacterial activity against Salmonella (Sal) and Staphylococcus aureus (S. aureus) bacterial strains, providing promising high application potential. Herein, different from the bare ZnO NPs, for Ag@ZnO/MgAC nanocomposites, Ag@ZnO NPs functioned as an effective photocatalyst under visible light illumination, in which, incorporated Ag atoms in the ZnO crystal structure caused the increase in a larger number of lattice defect sites. Benefiting from the strong surface plasmon resonance (SPR) effect of Ag and energy band matching between ZnO and Ag, the visible light absorption capacity and the separation of the photogenerated charge carriers were promoted. Therefore, the MB degradation efficiency of Ag@ZnO/MgAC was considerably accelerated in the presence of produced radicals from visible light illumination.

Flavonol glycosides from Fissistigma maclurei.

Two new flavonol glycosides, fissmacosides A (1) and B (2) along with two known flavonol glycosides, kaempferol 3-O-α-l-rhamnopyranosyl-(1→6)-ß-d-galactopyranoside (3) and kaempferol 3-O-ß-d-glucopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→6)-[4-(E)-feruloyl]-ß-d-galactopyranoside (4) were isolated from the methanol extract of the leaves of Fissistigma maclurei Merr. Their structures were determined on the basis of extensive spectroscopic methods, including 1D-, 2D-NMR, and MS data.

Unusual Rh nanocrystal morphology control by hetero-epitaxially growing Rh on Au@Pt nanowires with numerous vertical twinning boundaries.

Simultaneously growing multiple nanocrystallites in a crowded space can cause a shortage of precursors, and this can lead to a vertical growth of nanocrystallites on a given substrate. The presence of surfactant-surfactant interactions among adjacent nanocrystals can also place a unique structural constraint on the growing nanocrystallites, resulting in novel nanocrystal facet control. Herein, we report the growth of Rh on Au@Pt nanowires with multiple twinning boundaries, which are found along the entire nanowire length. The Au@Pt nanowires exhibit numerous bead-like structures, resulting from the preferred Pt deposition on the twinning boundaries, which can serve as nucleation sites for Rh. The heteroepitaxial growth of Rh on the Au@Pt nanowires results in unusual crystal growth behaviours. First, novel morphologies of Rh nanorods, nanoplates, and tangled manes are obtained temperature-dependently, which are not obtained in the absence of the Au@Pt nanowire substrate. Secondly, the thickness of vertically grown nanorods and nanoplates is tightly controlled. We also report the structure-catalytic activity relationship on the catalytic hydrogenation of phthalimides by the new Rh nanostructures.

Facet-controlled {100}Rh-Pt and {100}Pt-Pt dendritic nanostructures by transferring the {100} facet nature of the core nanocube to the branch nanocubes.

Facet-controlled dendritic nanostructures are expected to exhibit excellent catalytic properties because both aggregation-free nature and controlled facet-originated activity and selectivity can be accomplished. However, such examples are extremely rare due to the incompatibility of the dendrite formation process with the usage of surface-stabilizing moieties, which are typically used to control facets. Herein, we demonstrate that regiospecific growth on a facet-controlled core nanoparticle can induce the facet-control of the branch nanoparticles. Specifically, facet-controlled dendritic nanostructures of {100}Rh-Pt and {100}Pt-Pt can be conveniently prepared by transferring the crystallographic behaviour of the {100}Pt dendritic core nanocube to the {100}Rh or {100}Pt branch nanocubes.

Rationally synthesized five-fold twinned core-shell Pt3Ni@Rh nanopentagons, nanostars and nanopaddlewheels for selective reduction of a phenyl ring of phthalimide.

Surface-energy fine-tuned five-fold twinned nanostructures with a core-shell Pt3Ni@Rh structural motif, namely, a core-shell Pt3Ni@Rh pentagon, a core-shell Pt3Ni@Rh starfish, and a paddlewheel with a Pt3Ni crankshaft and two Rh five-fold starfish wheels, are prepared by rationally designed stepwise heteroepitaxial growth. Unusual selective hydrogenation of the phenyl ring in phthalimide is accomplished with moderately active core-shell Pt3Ni@Rh pentagons and starfish-like nanoparticles. The most active paddlewheel structure proceeds to further reduce one carbonyl group, indicating the sequential nature of phthalimide reduction by Rh nanoparticle catalysis.

Axially twinned nanodumbbell with a Pt bar and two Rh@Pt balls designed for high catalytic activity.

A fail-proof synthetic strategy has been developed for a multiply twinned dumbbell-shaped Rh@Pt nanostructure, which exhibits a superior electrocatalytic activity for methanol oxidation reaction. The unusually high electrocatalytic activity has been attributed to the synergistic effects of crystal twinning and core-shell structure.

Fabrication of hierarchical Rh nanostructures by understanding the growth kinetics of facet-controlled Rh nanocrystals.

By understanding the structural relationship among three shape-controlled Rh nanostructures, namely, {111} nanotetrahedrons, {111} tetrahedral nanoframes, and <111> skeletal nanotetrapods, we could prepare novel hierarchical dendritic Rh nanostructures with <111> Rh arms as linkers between tetrahedral shaped nanocrystals.

High yield synthesis of catalytically active five-fold twinned Pt nanorods from a surfactant-ligated precursor.

The CO-assisted thermal decomposition of a new, surfactant-ligated Pt precursor, [Pt(acac)(NHR)](n) (n = 2, 3; R = C(18)H(37)), gives structurally uniform five-fold twinned Pt nanorods. The Pt nanorods, mostly covered by {100} facets, exhibit much enhanced electrocatalytic activity over {100} faceted Pt nanocubes, indicating the superior catalytic performance due to the presence of the reactive twinning interface.