Aqueous Solution Synthesis of Pt–M (M = Fe, Co, Ni) Bimetallic Nanoparticles and Their Catalysis for the Hydrolytic Dehydrogenation of Ammonia Borane

Platinum-based bimetallic nanocatalysts have attracted much attention due to their high-efficiency catalytic performance in energy-related applications such as fuel cell and hydrogen storage, for example, the hydrolytic dehydrogenation of ammonia borane (AB). In this work, a simple and green method has been demonstrated to successfully prepare Pt–M (M = Fe, Co, Ni) NPs with tunable composition (nominal Pt/M atomic ratios of 4:1, 1:1, and 1:4) in aqueous solution under mild conditions. All Pt–M NPs with a small size of 3–5 nm show a Pt <i>fcc</i> structure, suggesting the bimetallic formation (alloy and/or partial core–shell), examined by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray absorption fine structure (XAFS) analysis. The catalytic activities of Pt–M NPs in the hydrolytic dehydrogenation of AB reveal that Pt–Ni NPs with a ratio of 4:1 show the best catalytic activity and even better than that of pure Pt NPs when normalized to Pt molar amount. The Ni oxidation state in Pt–Ni NPs has been suggested to be responsible for the corresponding catalytic activity for hydrolytic dehydrogenation of AB by XAFS study. This strategy for the synthesis of Pt–M NPs is simple and environmentally benign in aqueous solution with the potential for scale-up preparation and the <i>in situ</i> catalytic reaction

Gold–Silver Hybrid Nanostructures for Efficient Near-Infrared Photothermal Conversion: Core–Shell Configuration of Multipod and Hollow Cage

Gold–silver hybrid nanostructures have emerged as promising candidates for efficient near-infrared (NIR) photothermal conversion due to their unique optical and electronic properties. In this study, we report on the synthesis and characterization of gold–silver core–shell nanostructures with Au multipods as the core and Ag hollow cage as the shell, exhibiting strong absorption in the NIR region, which is attributed to the coupled localized surface plasmon resonance (LSPR) effect. Benefiting from its large surface area and porous structure, an optimized photothermal conversion efficiency of 68.5% is achieved, evaluated using a water suspension under an 808 nm laser at a power density of 1.0 W cm–2. The photothermal stability was also investigated, revealing good durability after multiple cycles of heating and cooling. Our study demonstrates the potential of gold–silver core–shell hybrid nanostructures involving both multipods and hollow cages for efficient NIR photothermal conversion applications. These findings pave the way for further optimization of these nanostructures for various biomedical and industrial applications

Synthesis and Structure-Dependent Optical Properties of ZnO Nanocomb and ZnO Nanoflag

The structure-dependent optical properties of ZnO nanostructures have attracted considerable attention due to their fascinating optoelectronic properties and great structural diversity. Novel ZnO nanocomb and ZnO nanoflag have been successfully synthesized by chemical vapor deposition (CVD) method using Au nanoparticles (NPs) as the catalyst at the deposition temperatures of 900 and 950 °C, respectively. X-ray diffraction and high-resolution transmission electron microscopy results show that the ZnO nanocomb handle and its teeth grow in [01̅11] and [0001] orientations, respectively, while the ZnO nanoflag sheet and its pole grow along [0001] and [21̅1̅0] orientations, respectively. Au NPs as well as deposition temperature played an important role in the growth of the nanocomb handle and nanoflag pole. Synchrotron-based scanning transmission X-ray microscopy (STXM) reveals the thickness distribution and the crystallinity of ZnO nanocomb and ZnO nanoflag. For the near-surface emission, photoluminescence and cathode luminescence spectra of these two ZnO nanostructures show band gap emission from both nanocomb and nanoflag but green emission from only ZnO nanocomb. Synchrotron-based two-dimensional X-ray absorption near-edge structure–X-ray excited optical luminescence (2D XANES–XEOL) further reveals that the green (defect) emissions come from both the surface and bulk of nanostructures. In the ZnO nanocomb, the O excitation channel contributes more favorably to the band gap emission compared to the defect emission, while the Zn excitation channel contributes less favorably to the band gap emission than the defect emission. Meanwhile, ZnO nanoflag displays an excellent crystallinity with weak defect emission; the Zn and O excitation channels both contribute predominantly to the band gap emission

Additional file 1: of Genetic analyses in a cohort of 191 pulmonary arterial hypertension patients

Table S1. PAH panel genes. Table S2. Variants of unknown significance (VUS) detected in the panel genes. Table S3. CNVs in ENG and ACVRL1 by panelcn.MOPS and MLPA. Table S4. Genotype-phenotype correlation between biallelic EIF2AK4 mutations carriers and other PAH patients. Figure S1. Molecular genetic testing schedule. Figure S2. 4 HPAH families without an identified causative mutation. Figure S3. GC content in BMPR2, ENG and ACVRL1. (DOCX 1809 kb

Structural Dependence of Platinum Nanostructures on Catalytic Performance in Aromatic Azo Compound Reaction Investigated by X‑ray Absorption Fine Structure Spectroscopy

Uniform one-dimensional Pt nanowires prepared by etching FePt nanowires precursor exhibit high conversion yield and selectivity in aromatic azo compounds reaction compared to the other Pt-based catalysts, such as Pt nanorods and Pt nanoparticles. The X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) were employed to investigate the electronic structure and short-range local environment of the three Pt nanostructures, revealing that the high density of unsaturated coordinated atoms in the short-range local structure of Pt nanowires contribute to the superior catalytic performance of the nanowires. Furthermore, the quasi in situ XANES was carried out to monitor the electronic structural evolution of the Pt nanowires during the different stages in the whole reaction process, which further clarify the Pt–OH involved catalytic reaction mechanism. This work delineates the correlation between catalytic performance and structural sensitivity of Pt-based catalysts investigated by X-ray absorption spectroscopy

Facile Synthesis of Graphene/Metal Nanoparticle Composites via Self-Catalysis Reduction at Room Temperature

Graphene/metal nanoparticle (NP) composites have attracted great interest for various applications as catalysts, electrodes, sensors, etc., due to their unique structures and extraordinary properties. A facile synthesis of graphene/metal NP composites with good control of size and morphology of metal NPs is critical to the practical applications. A simple method to synthesize graphene/metal NPs under a controllable manner via a self-catalysis reduction at room temperature has been developed in this paper. At first, metal NPs with desirable size and morphology were decorated on GO and then used as catalyst to accelerate the hydrolysis reaction of NaBH₄ to reduce the graphene oxide. Compared to the existing methods, the method reported here features several advantages in which graphene/metal NPs are prepared without using toxic and explosive reductant, such as hydrazine or its derivatives, making it environmentally benign, and the reaction can be processed at room temperature with high efficiency and in a large range of pH values. The approach has been demonstrated to successfully synthesize graphene composites with various metal NPs in large quantity, which opens up a novel and simple way to prepare large-scale graphene/metal or graphene/metal oxide composites under mild conditions for practical applications. For example, graphene/AuNP composites synthesized by the method show excellent catalytic capability

Additional file 2: of Physiological, hematological and biochemical factors associated with high-altitude headache in young Chinese males following acute exposure at 3700Â m

The incidence of mild, moderate and severe headaches after ascent to 3700 m altitude. (DOCX 16 kb

PCR products of DSPP alleles in splicing vector pLRT transfected into 293T and COS-1 cells.

<p>From left to right: D2000 marker, 293T cell control, naïve pLRT, mutant DSPP allele and wild type DSPP allele in 293T cells, D2000 marker, COS-1 cell control, naïve pLRT, mutant DSPP allele and wild type DSPP allele in COS-1 cells.</p

The family tree of the pedigree.

<p>The arrow shows the proband IV₁₂.</p

Additional file 3: of Physiological, hematological and biochemical factors associated with high-altitude headache in young Chinese males following acute exposure at 3700Â m

The Shapiro-Wilk normality test of parameters at 50 m and 3700 m. (DOCX 12 kb