Diachronic evolvement from tetra-icosahedral to quasi-hexagonal close-packed bimetal clusters.

Here we report a diachronic evolvement from tetra-icosahedral Au30Ag12(C[triple bond, length as m-dash]CR)24 to quasi-hcp (hexagonal close-packed) Au47Ag19(C[triple bond, length as m-dash]CR)32 via a one-step reduction, in which the size/structure conversion of the two clusters is not a typical Oswald growth process, but involves interface shrinking followed by core rearrangement and surface polymerization. Au30Ag12(C[triple bond, length as m-dash]CR)24 has an aesthetic Au18Ag8 kernel that is composed of four interpenetrating Au10Ag3 icosahedra, while Au47Ag19(C[triple bond, length as m-dash]CR)32 has a twisted Au19 core capped by a Au12Ag19 shell that are stacked in a layer-by-layer manner with a quasi-hcp pattern. The discovery of the two clusters not only provides further evidence for icosahedral clusters with longer excited-state lifetime compared to hcp-like clusters, but also discloses a double increase in catalytic reactivity for electrocatalytic oxidation of ethanol over quasi-hcp clusters in comparison with icosahedral clusters. This work provides the rationale for reversing the bottom-up growth process to remake bimetal clusters.

One-pot synthesis of rugged PdRu nanosheets as the efficient catalysts for polyalcohol electrooxidation.

Recently, intensive attention has been attracted to the two-dimensional metal nanosheets, owing to their excellent electrocatalytic performance for direct alcohol fuel cells (DAFCs). Herein, PdRu nanosheets have been synthesized successfully by a facile one-pot method. The rugged nanosheet structure provided plentiful surface active sites to enhance the electrocatalytic activity. Moreover, benefiting from the synergistic effect and improved electronic structure, PdRu NSs exhibited splendid electrocatalytic performance in ethylene glycol oxidation reaction (EGOR) and glycerol oxidation reaction (GOR). Specifically, the mass activity of PdRu NSs was 1.72 and 3.69 times over those of Pd NSs and Pd/C catalysts in EGOR. Moreover, PdRu NSs displayed the largest mass activity in GOR, 1.48 and 2.47 times as large as Pd NSs and Pd/C catalysts. The results of stability tests demonstrated that the durability of PdRu NSs was the highest among the obtained catalysts. This work plays a directive role on the in-depth engineering on Pd-based catalysts with nanosheet architectures.

Integrating chemical profiling and network pharmacology analysis based on anti-inflammatory effects for quality control of Scutellaria barbata.

INTRODUCTION: With the wide application of Scutellaria barbata D. Don for hepatitis and mastitis, its quality control issues have also received increasing attention. Based on the multi-component and multi-target characteristics of traditional Chinese medicine, there is an urgent need to establish a quality evaluation system. OBJECTIVES: This study intends to integrate the "quality-activity-quantification" strategy and establish an activity-related quality control method to ensure the safety and effectiveness of S. barbata. MATERIAL AND METHODS: Ultra-high performance liquid chromatography/ion mobility-quadrupole time-of-flight mass spectrometry (UPLC/IM-QTOF-MS) was used to characterize the chemical components of S. barbata, and network pharmacological analysis was carried out on the identified components. The index components were determined on the basis of comprehensive activity prediction results and content information. At the same time, the contents of 16 batches of S. barbata from different origins were determined. RESULTS: A total of 94 compounds were identified according to mass spectrometric data, 12 of which were isolated and structure-confirmed by nuclear magnetic resonance technology. Network pharmacological analysis was applied to predict their key targets and the major pathways mediating their anti-inflammatory effects. On the basis of comprehensive activity prediction and content information, five components were chosen as crucial quality indicators of S. barbata, including scutellarin, scutellarein, luteolin, apigenin, and hispidulin. CONCLUSION: In this study, 16 different S. barbata batches were compared, and five quality indicators were determined on the basis of qualitative and activity results. The present study provides useful information for evaluating the quality of S. barbata in different areas, and also provides a new basis for the development of quality evaluation methods.

Surface Plasmon Resonance Boost Electrocatalytic Alcohol Oxidation over Three-Dimensional PdM (M = Au, Ag, Cu) Nanosheet Assemblies.

Photoelectrocatalytic nanomaterials are promising for direct alcohol fuel cells, but the construction of high-efficiency catalysts remains difficult. We herein successfully synthesized three-dimensional (3D) PdM nanosheet assemblies (PdM NSAs, M = Au, Ag, and Cu) through a seed-mediated growth method, which displayed a typical 3D nanoflower morphology assembled from many two-dimensional ultrathin nanosheets. Due to the open 3D structure and the synergistic and electronic effects between Pd and Ag, the optimized PdAg NSAs showed the highest mass activity (9378 mA mg-1) for the ethylene glycol oxidation reaction. More interestingly, when irradiated with visible light, the mass activity increased to 14 590 mA mg-1, 12.1 times higher than that of the commercial Pd/C (1205 mA mg-1). In addition, the as-obtained catalysts also showed better long-term durability than that of the commercial Pd/C under the condition of with or without visible-light illumination. This work highlights the utilization of light energy in designing excellent photoelectrocatalysts to promote the photoelectrocatalytic performance of anode catalysts for fuel cells.

A review of the role and mechanism of surfactants in the morphology control of metal nanoparticles.

Although great progress has been made in the synthesis of metal nanoparticles, good repeatability and accurate predictability are still difficult to achieve. This difficulty can be attributed to the synthetic method based primarily on observation and subjective experience, and the role of many surfactants remains unclear. It should be noted that surfactants play an important role in the synthetic process. Understanding their function and mechanism in the synthetic process is a prerequisite for the rational design of nanocatalysts with ideal morphology and performance. In this review article, the function of surfactants is introduced first, and then the mechanism of action of surfactants in controlling the morphology of nanoparticles is discussed according to the types of surfactants, and the promoting and sealing effects of surfactants on the crystal surface is revealed. The relationship between surfactants and the morphology structure of nanoparticles is studied. The removal methods of surfactants are discussed, and the existing problems in the current development strategy are summarized. Finally, the application of surfactants in controlling the morphology of metal nanocrystals is prospected. It is hoped that the review can open up new avenues for the synthesis of nanocrystals.

Salidroside simultaneously reduces de novo lipogenesis and cholesterol biosynthesis to attenuate atherosclerosis in mice.

Salidroside is a kind of phenylethanoid glycoside and widespread in the plants from Rhodiola and Ligustrum species. Our previous study has reported that salidroside can prevent atherosclerosis progression by ameliorating glyerolipid and glycerophospholipid metabolism in apoE-deficient (apoE-/-) mice. However, its effect on neutral lipids and underlying mechanism remains largely unclear. Here we investigated the molecular mechanism of salidroside action from the perspective of metabolic regulation by integrating metabonomics and transcriptomics pattern. The results showed that salidroside significantly reduced cholesterols, esterified cholesterols, fatty acids, unsaturated fatty acids and triacylclycerols biosynthesis in liver through down-regulating the genes expressions of sterol regulatory element-binding proteins (Srebf1 and Srebf2). The expressions of SREBPs targeted and downstream genes, such as the encoding genes of fatty acid synthase (Fasn), glycerol-3-phosphate acyltransferase (Gpam), stearoyl-CoA desaturase (Scd), 3-hydroxy-3-methylglutaryl-CoA reductase (Hmgcr), and proprotein convertase subtilisin/kexin type 9 (Pcsk9), were also inhibited after salidroside administration. ATP citrate lyase gene (Acly) that encodes an important enzyme producing acetyl-CoA for cholesterol and fatty acid biosynthesis significantly decreased after treatment as well. Moreover, one of ketone body products, 3-hydroxybutyrate, was significantly up-regulated in drug-treated group, indicating that fatty acid degradation was accelerated by salidroside at the same time. Our findings identify salidroside as a regulator of lipid homeostasis in atherosclerotic mice, suggesting its potential to be an alternative medicine for lowering the risks of atherosclerosis-related diseases.

Hollow V-Doped CoMx (M = P, S, O) Nanoboxes as Efficient OER Electrocatalysts for Overall Water Splitting.

Hollow nanostructures with intricate interior and catalytic effects have been the focus of researchers in energy conversion and storage. Although tremendous efforts have been made, the fabrication of well-defined hollow nanostructures has been rarely reported due to the limitations of the synthetic methods. Herein, we have proposed a general synthetic strategy for the construction of V-doped CoMx (M = P, S, O) nanoboxes (NBs), where the doped V effectively modifies the electronic structure of CoMx to provide a favorable surface electrochemical environment for the adsorption of reaction intermediates (*O, *OH, and *OOH), leading to a significant enhancement in electrocatalytic performance. More importantly, the hollow nanostructures can expose abundant surface active areas and promote the chemical adsorption of reactants and intermediates, greatly contributing to the promotion of electrocatalytic performance. Impressively, the optimal V-doped CoS2 NBs show excellent electrocatalytic oxygen evolution reaction (OER) performance with an overpotential of only 290 mV at 10 mA cm-2, along with outstanding overall water-splitting performance. This work supplies pivotal insights for constructing high-performance OER catalysts on the basis of electronic and geometric engineering.

Tiny Ir doping of sub-one-nanometer PtMn nanowires: highly active and stable catalysts for alcohol electrooxidation.

One-dimensional (1D) Pt-based nanowires (NWs) materials serve as efficient catalysts for alcohol electrocatalysis. However, precisely tailoring their size towards sub-one-nanometer scale has been verified as an effective method for enhancing electrocatalytic properties, which is rarely studied. In this work, we developed a one-pot simple yet efficient method for synthesizing a kind of sub-one-nanometer tiny Ir-doped PtMn NWs. The prepared PtMnIr NWs have an ultrathin structure with a mean diameter of around only 0.97 nm (about 3-5 atomic thickness), which display large surface areas and promote superficial Pt atom utilization. With the robust tiny Ir incorporation, the composition-optimized Pt74Mn21Ir5 NWs showed enhanced mass activity, which was 1.51 and 1.53 times higher than those of non-Ir-doped Pt79Mn21 NWs for acidic ethanol oxidation reaction (EOR) and methanol oxidation reaction (MOR). Moreover, benefiting from the atom-level ultrathin size and well-tuned ligand effect from Ir to PtMn, the EOR/MOR mass activities of sub-nanometric Pt74Mn21Ir5 NWs were 3.99- and 3.98-fold higher than those of Pt/C catalysts. More importantly, after successive EOR and MOR CV tests, the Ir-doped PtMn NWs still maintained 85.6% and 73.4% of the initial mass activity, which were much better than those of Pt79Mn21 NWs, Pt NWs, and Pt/C catalysts. This work could be extended to engineering other advanced materials with super sub-one-nanometer structure, which is beneficial for largely improving the catalytic performance.

3D ZnIn2S4 nanosheets decorated ZnCdS dodecahedral cages as multifunctional signal amplification matrix combined with electroactive/photoactive materials for dual mode electrochemical - photoelectrochemical detection of bovine hemoglobin.

The construction of dual mode sensor has gained tremendous attention due to its high accuracy and sensitivity compared with a single-response system. Herein, a novel dual mode sensing platform based on a 3-dimensional (3D) ZnCdS/ZnIn2S4 double-shelled dodecahedral cages (DSDCs) is fabricated as the electrochemical (EC) - photoelectrochemical (PEC) multifunctional signal amplification matrix for the highly selective detection of bovine hemoglobin (BHb). To achieve simple and fast detection of BHb, Au@Cu2O and SnO2/SnS2 are acted as EC - PEC signal indicators, respectively. More interestingly, the electroactive Au@Cu2O and photoactive SnO2/SnS2 are assembled on the 3D ZnCdS/ZnIn2S4 DSDCs, which could effectively increase the electron transfer process, consequently amplifying the readout of the dual mode responses. Besides, polydopamine (PDA) is used as a monomer for protein imprinting. Under the optimized conditions, the dual mode sensor exhibits a wide linear concentration range from 10-19 mg mL-1 to 10-1 mg mL-1 with a low detection limit 6.5 × 10-20 mg mL-1. Furthermore, the excellent selectivity, stability and acceptable reproducibility of the designed sensor will offer an alternation for the detection of other biomacromolecules in clinic diagnosis field.

Triterpenoids From Alisma Species: Phytochemistry, Structure Modification, and Bioactivities.

Plants from Alisma species belong to the genus of Alisma Linn. in Alismataceae family. The tubers of A. orientale (Sam.) Juzep, also known as Ze Xie in Chinese and Takusha in Japanese, have been used in traditional medicine for a long history. Triterpenoids are the main secondary metabolites isolated from Alisma species, and reported with various bioactive properties, including anticancer, lipid-regulating, anti-inflammatory, antibacterial, antiviral and diuretic activities. In this brief review, we aimed to summarize the phytochemical and pharmacological characteristics of triterpenoids found in Alisma, and discuss their structure modification to enhance cytotoxicity as well.

Tunable long-chains of core@shell PdAg@Pd as high-performance catalysts for ethanol oxidation.

High performance nanomaterial catalysts have attracted great attention on the application for the direct alcohol fuel cell. To improve the catalytic behavior, it is a challenge to modulate the surface structure and morphology of catalysts. We integrated properties of advanced networks nanostructure and core@shell structure to form a series of PdAg@Pd worm-like networks catalysts. Importantly, the composition-optimized Pd76Ag24 WNWs exhibited excellent catalytic performance towards ethanol oxidation reaction compared to that of commercial Pd/C catalysts in alkaline media. The mass activity of Pd76Ag24 WNWs is 3.55 times higher than that of commercial Pd/C catalysts for EOR. Moreover, the Pd76Ag24 WNWs also showed superior stability after 250 successive cycles and kept far higher residual activities than that of the other catalysts. The synthesis of PdAg@Pd worm-like networks catalysts provides a reference to well combine the advantages of core@shell and networks structure to form high performance catalysts application for DEFC.

Efficient polyalcohol oxidation electrocatalysts enabled by PtM (M = Fe, Co, and Ni) nanocubes surrounded by (200) crystal facets.

Due to the high-density (200) crystal planes and abundant active sites, cubic platinum nanomaterials have become outstanding electrocatalysts in promoting fuel cell reactions. However, because of the fact that the facet-controlled synthesis is difficult, it is still a grand challenge to synthesize a sequence of Pt-based nanocubes via a universal method. Herein, we report a general and simple eco-friendly solvothermal method to prepare (200)-enclosed PtM nanocubes. Different from the other nanomaterials, nanocubes are conducive to mass transfer. Moreover, the synergistic and electronic effects between M and Pt are profitable to improve the utilization of precious metals. We used (200)-encapsulated nanocrystals to evaluate their electrocatalytic performance towards glycerol and ethylene glycol oxidation reactions in an alkaline medium. In particular, Pt4Co nanocubes showed superior mass activities in glycerol and ethylene glycol oxidation reactions, which are 6.2- and 5.0-fold higher than those obtained for commercial Pt/C catalysts, respectively. Meanwhile, Pt4M catalysts manifested excellent stability in the endurance test, which is attributed to the alloying effect promoting the electrooxidation of intermediates. Our study provides an ideal method for the construction of Pt-based bimetallic nanocubes, which can be used for anode reactions of polyol fuel cells and beyond.

Trimetallic platinum-nickel-palladium nanorods with abundant bumps as robust catalysts for methanol electrooxidation.

The development of high-performance catalysts is of great importance in direct alcohol fuel cells. One dimensional nanorods catalysts are hopeful candidates as efficient alcohol electrocatalysis. However, it is desirable to precisely modulate the surface morphology of one dimensional nanorods nanocrystals to acquire better catalytic property. We effectively integrate properties of robust one dimensional nanorods, core@shell structure, and ternary nanoalloy into a new PtNiPd@Pt core@shell nanorods with high density bumps on the surface for potential better catalytic behaviors. Notably, those unique structures make the PtNiPd@Pt nanocrystals display favorable electrocatalytic performance towards methanol oxidation reaction. Specifically, the composition-optimized PtNi0.20Pd0.52 nanorods exhibit the highest methanol oxidation reaction specific activity of 18.01 mA cm-2 among PtNiPd@Pt catalysts in alkaline condition. The specific activity is 8.5 times higher than that of Pt/C catalysts. Moreover, electrochemical stability measurements also confirm the better reaction endurance of PtNi0.20Pd0.52 nanorods. Our work provides a reference to well tune the fine surface structure on one dimensional nanorods catalysts in the direction of superior electrocatalytic behaviors.

From bimetallic PdCu nanowires to ternary PdCu-SnO2 nanowires: Interface control for efficient ethanol electrooxidation.

At present, although a large number of palladium-based nanowire electrocatalysts have been prepared, there are few reports on nanowires containing rich metal oxides. Herein, porous PdCu alloy nanowires and PdCu-SnO2 nanowires were prepared by using a galvanic displacement synthesis method. Due to their one-dimensional structure, rough surfaces with non-homogeneous edges, electronic effect, and the advanced PdCu/SnO2 interface of the as-synthesized PdCu-SnO2 nanowire catalysts, they exhibited a mass activity of 7770.0 mA mg-1 towards ethanol oxidation, which was 7.6-fold higher than that of Pd/C catalysts (1025.0 mA mg-1). In addition, they behaved strong durability upon chronoamperometry and continuous cyclic voltammetry tests. The electrochemical measurements demonstrated that SnO2 was introduced into the PdCu/SnO2 interface, which promoted the oxidation of ethanol at a lower potential and accelerated the oxidation of Pd-COads via SnO2-OHads to regenerate the active sites. This research highlights the significance of introducing metal oxides into the nanostructure interface, and the performance of Pd-containing catalysts towards ethanol oxidation reaction was greatly improved.

Ultrafine PtCuRh nanowire catalysts with alleviated poisoning effect for efficient ethanol oxidation.

As a green power source, direct ethanol fuel cells (DEFCs) have broad application prospects. However, most catalysts of DEFCs still exhibit defects, such as the difficulty of C-C bond cleavage, serious CO poisoning and limited catalytic activity. Here, we report ultrafine PtCuRh nanowires (NWs) with outstanding anti-CO-poisoning properties and enhanced activity. The average diameter of the ultrafine PtCuRh NWs is about 1.49 nm, effectively improving the atomic utilization efficiency (UE) of platinum. Owing to the combination of an ultrafine nanostructure, good electronic interaction and the high UE of Pt atoms, the optimized ultrafine PtCuRh NWs/C display superior electrocatalytic activity and stability compared with commercial Pt/C for the ethanol oxidation reaction (EOR). More importantly, further electrochemical results demonstrate that the incorporation of Rh is beneficial for enhancing the antipoisoning capability for some CO-like intermediates. Meanwhile, the synthetic method in this report is robust and universal, and can also be applied to the synthesis of ultrafine trimetallic PtCuPd and PtCuIr nanowires.

High-density surface protuberances endow ternary PtFeSn nanowires with high catalytic performance for efficient alcohol electro-oxidation.

Developing cost-effective catalysts with superb activity and stability to alcohol electro-oxidation is a decisive factor towards the progress of direct alcohol fuel cells (DAFCs). Rationally utilizing the architectural and surface microstructural sensitivity of nanocatalysts can significantly increase their electrocatalytic properties. Here, we report an appropriate route that allows the fabrication of ultrafine PtFeSn nanowires (NWs) with tunable compositions. Interestingly, the addition of Sn reconstructed the surface microstructures, making ultrafine 1D NWs rich in a large number of surface protuberances, which may facilitate the oxidation of ethanol and methanol. Impressively, further catalytic studies demonstrate that all the PtFeSn NWs exhibit excellent catalytic capabilities for ethanol oxidation reaction (EOR) and methanol oxidation reaction (MOR), and display composition-related electrocatalytic activity with Pt1Fe0.20Sn0.46 NWs, possessing the highest activity for EOR and MOR. In addition, the trimetallic PtFeSn NWs exhibit significant meliorative durability relative to PtFe NWs and commercial Pt/C. The superb electrocatalytic performance is ascribed to its one-dimensional (1D) structure, atomic-level fine diameter, synergistic effect among Pt, Fe, and Sn components and abundant protuberances on the surface. Thus, this study highlights the significance of accurate structure- and surface-controlled Pt-based NWs for electrocatalysis and provides a universal approach for designing multi-component catalysts.

Three-dimensional palladium-rhodium nanosheet assemblies: Highly efficient catalysts for methanol electrooxidation.

Even though substantial attention has been focused on exploring promising palladium-based catalysts, the creation of electrocatalysts with simultaneous high activity and reduced cost for fuel cell reactions remains a challenge. Here, we report on the design and construction of a new class of three-dimensional (3D) palladium-rhodium (PdRh) nanosheet assembly (NSA) catalysts through a seed-mediated growth method. Interestingly, the well-defined NSAs with optimized electronic structures and highly open 3D structures exhibit greatly enhanced electrocatalytic activity toward the methanol oxidation reaction (MOR). In particular, optimized Pd86Rh14 NSAs have a mass activity of 1672.7 mA mg-1 for the MOR, 5.4 times higher than that of commercial Pd/C catalysts (303.8 mA mg-1). More importantly, these PdRh NSAs also display improved MOR stability, with stable high electrocatalytic performance for more than 250 potential cycles.

Novel networked wicker-like PtFe nanowires with branch-rich exteriors for efficient electrocatalysis.

The construction of Pt-based networked nanowire nanocatalysts with high performance is significant in the application of direct alcohol fuel cells. However, it is still a challenge to precisely regulate the surface structure and further improve their catalytic behavior. For this purpose, we have synthesized a series of novel networked wicker-like PtFe nanowire catalysts, different from previous networked nanowire catalysts with smooth surfaces, and the PtFe catalysts possess branch-rich exteriors on the rough surface of each nanowire similar to wickers and they interconnect with each other, which lead to rich steps and defects. Importantly, after electrochemical tests, the composition-optimized Pt3Fe nanowires were found to exhibit superior catalytic performance towards the ethanol oxidation reaction (EOR) and methanol oxidation reaction (MOR) compared to that of commercial Pt/C catalysts in acid media. In particular, the specific activities of Pt3Fe nanowires are 7.3 and 7.1 times higher than those of the Pt/C catalysts for EOR and MOR, respectively. In addition, the Pt3Fe nanowires also show the best durability among these catalysts after 1000 successive cycles, and their residual activities are far better than those of the Pt/C catalysts. The synthesis of wicker-like networked PtFe nanowires offers a new guideline to tune the structure and composition of nanocatalysts for their use in direct alcohol fuel cells and beyond.

Monodispersed bimetallic platinum-copper alloy nanospheres as efficient catalysts for ethylene glycol electrooxidation.

Designing and fabricating highly active and efficient catalysts are of vital importance for the practical applications of direct ethylene glycol fuel cells (DEGFCs). In this study, we employ a feasible one-pot synthetic method to construct highly monodispersed PtCu nanospheres (NSs) as high-efficiency anode electrocatalysts for DEGFCs. Interestingly, the optimized carbon supported Pt1Cu1 NSs can display the highest mass activity of 2146.9 mA mg-1 in 1 M KOH + 1 M EG solution under the scan rate of 50 mV s-1, which is 1.9 times higher than that of commercial Pt/C catalysts. This is ascribed to the favorable electronic effect between Pt and Cu, which is beneficial for ethylene glycol oxidation reaction (EGOR) in fuel cells. Meanwhile, such monodispersed Pt1Cu1 NSs can also exhibit excellent durability, where the Pt1Cu1 catalyst retains 62.6% of the initial value after the cyclic voltammetry of 500 cycles. This work not only provides a significant approach for designing catalysts for fuel cells, but also constructs a novel class of active and stable electrocatalysts for EGOR.

Precise synthesis of monodisperse PdAg nanoparticles for size-dependent electrocatalytic oxidation reactions.

The fabrication of nanomaterials with tunable shape and size has attracted much attention in chemical and physical fields. It is particularly significant to study the effect of catalyst particle size on catalytic performance in the field of catalysis. At present, there are relatively few studies in this field, the main challenge lies in the difficulty of synthesizing catalysts with uniform size. If the particle size of a certain size is not uniform, it is meaningless to compare the catalytic performance with that of other catalysts for size effect. Herein, we successfully synthesized the monodisperse PdAg nanoparticles with three different sizes by changing the type of reducing agents. Among the three catalysts, the PdAg-S NPs (PdAg-Small nanoparticles) with an average size of 3.1 nm exhibited superior electrocatalytic performances of ethylene glycol and glycerol oxidation reactions, which were obviously better than others size PdAg NPs catalysts and commercial Pd/C catalyst. This work revealed the size effect of PdAg nanoparticles in the alcohols electrooxidation and provided a simple method in the design of different sizes of nanocrystals.