Island-in-Sea Structured PtFe Nanoparticles-in-Fe Single Atoms Loaded in Carbon Materials as Superior Electrocatalysts toward Alkaline HER and Acidic ORR.

In this work, PtFe nanoparticles (PtFe NPs) with the ordered internal structure and Pt-rich shells surrounded by plenty of Fe single atoms (Fe SAs) as active species (PtFe NP-in-Fe SA) loaded in the carbon materials are successfully fabricated, which are abbreviated as island-in-sea structured (IISS) PtFe NP-in-Fe SA catalysts. Moreover, the synergistic effect of O-bridging between PtFe NPs and Fe SAs, and the ordered internal structured PtFe NPs with Pt-rich shells of an optimal thickness contributes to the achievement of the local acidic environments on the surfaces of PtFe NPs in the alkaline hydrogen evolution reaction (HER) and the enhancement of the desorption rate of *OH intermediate in the acidic oxygen reduction reaction (ORR). In addition, the electronic interactions between PtFe NPs and dispersed Fe SAs cannot only provide efficient electrons transfer, but also prevent the aggregation and dissolution of PtFe NPs.

Synthetic Principles of Spiky Au Nanoparticles.

In this work, the synthetic principles of spiky Au nanoparticles (spiky Au NPs) with an average number of spikes of less than or equal to six and controlled core sizes by using Au nanorods as seeds (Au-NR seeds) are summarized on the basis of the results of a series of control experiments. In addition, one empirical equation that can roughly estimate the number of spiky Au NPs is proposed, demonstrated by the results of the products prepared from different aspect ratios of Au-NRs as seeds and non-Au-NR seeds. Moreover, the synthetic principles of spiky Au NPs are further demonstrated by taking the successful synthesis of a serials of spiky Au NPs.

Dimensional and Optoelectronic Tuning of Lead-free Perovskite Cs Bi I Br Single Crystals for Enhanced Hard X-ray Detection.

Inorganic Bi-based perovskites have shown great potential in X-ray detection for their large absorption to X-rays, diverse low-dimensional structures, and eco-friendliness without toxic metals. However, they suffer from poor carrier transport properties compared to Pb-based perovskites. Here, we propose a mixed-halogen strategy to tune the structural dimensions and optoelectronic properties of Cs Bi I Br (0≤n≤9).

Ethanol Oxidation via 12-Electron Pathway on Spiky Au@AuPd Nanoparticles Assisted by Near-Infrared Light.

In this work, ethanol oxidation reaction (EOR) via 12-electron (C1-12e) pathway on spiky Au@AuPd nanoparticles (NPs) with ultrathin AuPd alloy shells is achieved in alkaline media with the assistance of the near-infrared (NIR) light. It is found that OH radicals can be produced from the OH species adsorbed on the surfaces of Pd atoms led by surface plasmon resonance (SPR) effect of spiky Au@AuPd NPs under the irradiation of NIR light. Moreover, OH radicals play the key role for the achievement of EOR proceeded by the desirable C1-12e pathway because OH radicals can directly break the C-C bonds of ethanol.

The enhancement in the performance of ultra-small core-shell Au@AuPt nanoparticles toward HER and ORR by surface engineering.

In this work, ultra-small core-shell (USCS) Au@AuPt nanoparticles (NPs) with an optimal Pt-to-Au ratio were successfully prepared by the optimal etching treatment of USCS Au@AuPt NPs by Fe(III) ions to remove some exposed Au atoms on their outermost surfaces. The as-prepared USCS Au@AuPt NPs with Fe(III)-etching treatment for 2 h loaded on carbon black as catalysts (USCS Au@AuPt-NP/C catalysts) exhibit superior electrocatalytic activity and durability for both the hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) in acidic media. For instance, the overpotential of USCS Au@AuPt-NP/C catalysts toward the HER is 13 mV at a current density of -10 mA cm ( = 13 mV), which is much better than that of commercial Pt/C catalysts ( = 31 mV).

Controlled Iodine Phase Transfer of Covalent Organic Framework Membranes for Instant but Sustained Disinfection.

Freestanding membranes of CuCl-implanted TpPa covalent organic frameworks (COFs) were mechanochemically produced. The resulting membrane had a high I adsorption capacity (566.78 g·mol) in cyclohexane, which corresponds to 2.

Large-Area Monolayer Films of Hexagonal Close-Packed Au@Ag Nanoparticles as Substrates for SERS-Based Quantitative Determination.

In this work, quasi-spherical, small-sized, citrate-stabilized, core-shell (CS)-structured Au@Ag nanoparticles (NPs) with Ag shells of controlled thicknesses ( = 0, 1.25, 3.25, and 5.

Macroscopical monolayer films of ordered arrays of gold nanoparticles as SERS substrates for quantitative detection in aqueous solutions.

In this work, macroscopical monolayer films of ordered arrays of gold nanoparticles (MMF-OA-Au NPs) are successfully prepared at the interfaces of toluene-diethylene glycol (DEG) with a water volume fraction of 10% (no more than 25%), which can greatly reduce the electrostatic repulsion among NPs during the self-assembly due to the quick transfer of the remaining citrate ions into the DEG solutions containing water. Thanks to the uniformity in the intensity of SERS signals, the as-prepared MMF-OA-Au NPs transferred onto polydimethylsiloxane (PDMS) as SERS substrates (MMF-OA-Au NP@PDMS) can achieve quantitative detection of the analytes (such as crystal violet and malachite green) in aqueous solutions. Moreover, MMF-OA-Au NP@PDMS as SERS-based pH sensors can directly determine the pH value of the aqueous solution in the range of 3 to 10 by means of the established well-defined linear relationship with the intensity of the peak of COO without any calibration, instead of the intensity ratio of the Raman peaks of COO to 8a with further calculation.

Fe-Ni Alloy Nanoclusters Anchored on Carbon Aerogels as High-Efficiency Oxygen Electrocatalysts in Rechargeable Zn-Air Batteries.

In this work, Fe-Ni alloy nanoclusters (Fe-Ni ANCs) anchored on N, S co-doped carbon aerogel (Fe-Ni ANC@NSCA catalysts) are successfully prepared by the optimal pyrolysis of polyaniline (PANI) aerogels derived from the freeze-drying of PANI hydrogel obtained by the polymerization of aniline monomers in the co-presence of tannic acid (TA), Fe , and Ni ions. In addition, the optimal molar ratio of the TA, Fe , and Ni ions for synthesis of Fe-Ni ANC@NSCA catalysts are 1:2:5, which can guarantee the formation of carbon aerogel composed of quasi-2D porous carbon sheets and the formation of high-density Fe-Ni ANCs with an ultrasmall size between 2 to 2.8 nm.

Synthesis of Uniform Gold Nanorods with Large Width to Realize Ultralow SERS Detection.

In this work, we successfully demonstrate high-yield synthesis of high-quality gold nanorods (Au NRs) with width ranging from 6.5 nm to 175 nm by introducing heptanol molecules as secondary templating agents during cetyltrimethylammonium bromide-templated, seeded growth method. The results show that an appropriate concentration of heptanol molecules not only alter the micellization behavior of CTAB in water, but also help silver ions impact the symmetry-breaking efficiency of additional Au-NP seeds in addition to enhancing the utilization of gold precursors.

Fe(II)-Assisted one-pot synthesis of ultra-small core-shell Au-Pt nanoparticles as superior catalysts towards the HER and ORR.

In this work, uniform ultra-small core-shell Au-Pt nanoparticles (denoted as USCS Au-Pt NPs) with Au-decorated Pt surfaces are successfully prepared by Fe(ii)-assisted one-pot co-reduction of Au(iii) ions and Pt(ii) ions in a citrate solution. The as-prepared USCS Au38.4@Au9.

Facet-Dependent Long-Term Stability of Gold Aerogels toward Ethylene Glycol Oxidation Reaction.

In this work, a series of Au aerogels with different percentages of {110} facets (from ∼12 to 36%) were controllably prepared and then used to investigate their performance (specific activity and long-term stability) toward ethylene glycol oxidation reaction (EGOR), in which PNR represents the particle number ratio of 6 nm Au NPs to 50 nm Au NPs. It is found that their specific activity and long-term stability highly depend on the sum of the percentage of the {100} and {111} facets and the percentage of {110} facets, respectively. In addition, Au aerogels with the highest percentage of {110} facets can possess excellent long-term stability (retaining about 95% of the initial current) but still have excellent specific activity (about 90.

Synthesis of large gold nanoparticles with deformation twinnings by one-step seeded growth with Cu(ii)-mediated Ostwald ripening for determining nitrile and isonitrile groups.

In this work, uniform and large gold nanoparticles (Au NPs) including quasi-spherical (QS) Au NPs with average diameters of 70 to 196 nm and trisoctahedral (TOH) Au NPs with average diameters of 140 to 195 nm were successfully synthesized by controlling the concentration of Cu2+ ions and the particle number of 3 nm Au-NP seeds, respectively, using a one-step seeded growth method with Cu2+-mediated Ostwald ripening. It is found that because of the concentration-dependent under-potential deposition of Cu2+ ions (CuUPD), 3 nm Au-NP seeds are firstly changed into Au NPs with a controlled QS- or TOH shape at the initial growth stage, followed by the conformal growth of Au atoms onto the initially formed Au NPs due to Cu2+-mediated Ostwald ripening, in which the extra Au atoms come from the dissolution of in situ Au nuclei by the unavoidable self-nucleation. Moreover, the as-prepared QS Au NPs with a rough surface exhibit a better SERS performance for physically adsorbed probes (crystal violet, CV) than the TOH Au NPs with sharp tips and with a comparable size.

Tumor microenvironment-responsive multifunctional peptide coated ultrasmall gold nanoparticles and their application in cancer radiotherapy.

Two important features are required for promising radiosensitizers: one is selective tumor cell targeting to enhance the therapeutic outcome via lethal DNA damage and the other is rapid clearance to enable excellent biocompatibility for potential clinical application. Herein, ultrasmall gold nanoparticles (Au NPs) with diameter smaller than 5 nm were prepared and covered with a multifunctional peptide to endow them with selective tumor cell uptake capability. Combined with X-ray irradiation, the responsive Au NPs demonstrated superior radio-sensitizing toxicity and rapid renal clearance .

The impact of size and surface ligand of gold nanorods on liver cancer accumulation and photothermal therapy in the second near-infrared window.

Gold nanorods (GNRs) with longitudinal surface plasmon resonance (LSPR) peaks in second near-infrared (NIR-II) window have attracted a great amount of attention as photothermal transducer because of their inherently excellent photothermal transition efficiency, high biocompatibility and versatile surface functionalization. One key question for the application of these GNRs against tumors in vivo is which size/shape and surface ligand conjugation are promising for circulation and tumor targeting. In this study, we prepared a series of gold nanorods (GNRs) of similar aspect ratio and LSPR peaks, and thus similar photothermal transfer efficiency under irradiation of 980 nm laser, but with tunable size in width and length.

Decreased DC-SIGNR expression in hepatocellular carcinoma predicts poor patient prognosis.

Dendritic cell-specific intercellular adhesion molecule-grabbing non-integrin-related protein (DC-SIGNR) is a transmembrane receptor primarily involved in pathogen recognition by the innate immune system, with particular importance for viral recognition. DC-SIGNR may also be associated with tumorigenesis. The aim of the present study was to investigate the association between DC-SIGNR expression, development of hepatocellular carcinoma (HCC), and clinicopathological features.

Compressive Strain in Core-Shell Au-Pd Nanoparticles Introduced by Lateral Confinement of Deformation Twinnings to Enhance the Oxidation Reduction Reaction Performance.

In this work, quasi-spherical, uniform gold nanoparticles with rich deformation twinning (Au NPs) were first synthesized with the assistance of copper(II) ions. Then, these Au NPs were used as the cores for the fabrication of core-shell (CS) Au-Pd NPs with ultrathin Pd layers, which also can bear compressive strain because of the formation of corrugated structured Pd shells led by the lateral confinement imposed by deformation twinning in the Au cores. The presence of compressive strain in the CS Au-Pd NPs can result in the widening of the d-band width of the Pd shell and further the downshift of their d-band center, which can then improve the desorption ability of intermediates and still maintain the adsorption ability of the reactants because of the broad adsorption potential range.

Fabrication of Au aerogels with {110}-rich facets by size-dependent surface reconstruction for enzyme-free glucose detection.

In this work, a series of Au aerogels with exposed {110}-facets were successfully synthesized by Ostwald-ripening between two differently-sized gold nanoparticles (Au NPs). On the basis of the results of de-convoluting CV analysis and size variation of large Au NPs during their formation process, it is found that the size ratio (R) between two differently-sized Au NPs is crucial for the occurrence of surface reconstruction during the Ostwald-ripening process. Moreover, the R can be used to estimate the extent of surface reconstruction and the critical R for the occurrence of surface reconstruction in our case is about 5.

Size Control Synthesis of Monodisperse, Quasi-Spherical Silver Nanoparticles To Realize Surface-Enhanced Raman Scattering Uniformity and Reproducibility.

In this work, we reported the synthesis of monodisperse, quasispherical Ag nanoparticles (NPs) with sizes of 40-300 nm by using ascorbic acid reduction of a silver-ammonia complex onto preformed, 23 nm Ag-NP seeds in the aqueous solution with an optimal pH of about 9.6 at room temperature. The as-prepared Ag NPs with such a large size span (from 40 to 300 nm) and high quality by one-pot seeded growth method are reported for the first time to the best of our knowledge.

pH-Dependent growth of atomic Pd layers on trisoctahedral gold nanoparticles to realize enhanced performance in electrocatalysis and chemical catalysis.

In this work, the controlled epitaxial growth of ultrathin Pd shells of a few atomic layers (denoted as nL) on the surfaces of gold nanoparticle (Au NP) cores of different morphologies (trisoctahedral, cubic, and spherical shapes) in the presence of cetyltrimethylammonium chloride (CTAC) was achieved by regulating the pH value of the aqueous CTAC solution and finely tuning the amount of the Pd precursor. It was found that the critical shell thickness for epitaxial Pd growth at the optimal pH value was 4 atomic layers, taking {331}-faceted trisoctahedral (TOH) Au@Pd NPs as an example, on the basis of the results of atomic-resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) images. Moreover, the resulting TOH Au@Pd NPs (100.

Realizing enhanced luminescence of silver nanocluster-peptide soft hydrogels by PEI reinforcement.

Metal nanoclusters (NCs) are a new type of fluorescent nanomaterial composed of several to several tens of metal ions or atoms with a wide range of applications in the fields of catalysis, optics, and biomedicine. However, fluorescence quenching when existing as individuals in aqueous solutions greatly limits their applications. In this study, six-core Ag(i) NCs (Ag-NCs) were interacted with peptides (DD-5) in water to form soft hydrogels with the aggregation-induced emission (AIE) of Ag-NCs.

Decreased CRHBP expression is predictive of poor prognosis in patients with hepatocellular carcinoma.

Corticotropin releasing hormone binding protein (CRHBP) mediates the reaction between corticotropin releasing hormone (CRH) and corticotropin releasing hormone receptors (CRHRs). It is expressed in a number of organs, and the expression of CRHBP is associated with tumorigenesis and cancer progression. The aim of the present study was to investigate CRHBP expression levels in hepatocellular carcinoma (HCC) and its association with patient clinicopathological characteristics as well as prognosis.

Regulating Surface Facets of Metallic Aerogel Electrocatalysts by Size-Dependent Localized Ostwald Ripening.

It is well known that the activity and stability of electrocatalysts are largely dependent on their surface facets. In this work, we have successfully regulated surface facets of three-dimensional (3D) metallic Au aerogels by salt-induced assembly of citrate-stabilized gold nanoparticles (Au NPs) of two different sizes and further size-dependent localized Ostwald ripening at controlled particle number ratios, where m and n represent the size of Au NPs. In addition, 3D Au -Pd aerogels were further synthesized on the basis of Au aerogels and also bear controlled surface facets because of the formation of ultrathin Pd layers on Au aerogels.

Passively Q-switched mid-infrared laser pulse generation with gold nanospheres as a saturable absorber.

High-quality gold (Au) nanospheres (Au-NPs) with a diameter of 52 nm were prepared by the seeded growth method. The mid-infrared (MIR) nonlinear saturable absorption properties were measured by a balanced twin-detector measurement technique. With the as-prepared Au-NPs saturable absorber (SA), an efficient passively Q-switched laser was realized at 2.

Simple Synthesis of Au-Pd Alloy Nanowire Networks as Macroscopic, Flexible Electrocatalysts with Excellent Performance.

The present work introduces a new way to prepare Au-Pd alloy nanowire networks (NWNs) via deposition of Pd atoms onto Au nanowires in reaction media at room temperature without the aid of additional reducing agents. Thanks to their excellent colloidal stability in water as well as in ethanol, the resulting NWNs can be utilized to produce composite thin films with Nafion (perfluorinated sulfonic acid) with dimensions above dozens of square centimeters by means of solution casting on the glass substrate. Most importantly, these films can be easily transferred onto different solid substrates by lift-off technology.