The presence of trace CO impurity gas in hydrogen fuel can rapidly deactivate platinum-based hydrogen oxidation reaction (HOR) catalysts due to poisoning effects, yet the precise CO tolerance mechanism remains debated. Our designed Au@PtX bifunctional core-shell nanocatalysts exhibit excellent performance of CO tolerance in acidic solution during HOR and possess exceptional Raman spectroscopy enhancement. Through capturing and analyzing in situ Raman spectroscopy evidences on *OH, metal-O species and *CO evolution under 0.
View Article and Find Full Text PDFNickel-iron-based catalysts are recognized for their high efficiency in the oxygen evolution reaction (OER) under alkaline conditions, yet the underlying mechanisms that drive their superior performance remain unclear. Herein, we revealed the molecular OER mechanism and the structure-intermediate-performance relationship of OER on a phosphorus-doped nickel-iron nanocatalyst (NiFeP). NiFeP exhibited exceptional activity and stability with an overpotential of only 210 mV at 10 mA cm in 1 M KOH and a cell voltage of 1.
View Article and Find Full Text PDFSurface-enhanced Raman spectroscopy (SERS) has evolved significantly over fifty years into a powerful analytical technique. This review aims to achieve five main goals. (1) Providing a comprehensive history of SERS's discovery, its experimental and theoretical foundations, its connections to advances in nanoscience and plasmonics, and highlighting collective contributions of key pioneers.
View Article and Find Full Text PDFElectrocatalytic CO2 reduction reaction (CO2RR) for CH4 production presents a promising strategy to address carbon neutrality, and the incorporation of a second metal has been proven effective in enhancing catalyst performance. Nevertheless, there remains limited comprehension regarding the fundamental factors responsible for the improved performance. Herein, the critical role of Pd in electrocatalytic CO2 reduction to CH4 on Cu-based catalysts has been revealed at a molecular level using in situ surface-enhanced Raman spectroscopy (SERS).
View Article and Find Full Text PDFACS Appl Mater Interfaces
March 2024
Photocatalysis driven by plasmon-induced hot carriers has been gaining increasing attention. Recent studies have demonstrated that plasmon-induced hot carriers can directly participate in photocatalytic reactions, leading to great enhancement in solar energy conversion efficiency, by improving the catalytic activity or changing selectivity. Nevertheless, the utilization efficiency of hot carriers remains unsatisfactory.
View Article and Find Full Text PDFSurface-enhanced Raman scattering (SERS) can overcome the existing technological limitations, such as complex processes and harsh conditions in gaseous small-molecule detection, and advance the development of real-time gas sensing at room temperature. In this study, a SERS-based hydrogen bonding induction strategy for capturing and sensing gaseous acetic acid is proposed for the detection demands of gaseous acetic acid. This addresses the challenges of low adsorption of gaseous small molecules on SERS substrates and small Raman scattering cross sections and enables the first SERS-based detection of gaseous acetic acid by a portable Raman spectrometer.
View Article and Find Full Text PDFElectrolyte plays a crucial role in ensuring stable operation of lithium metal batteries (LMBs). Localized high-concentration electrolytes (LHCEs) have the potential to form a robust solid-electrolyte interphase (SEI) and mitigate Li dendrite growth, making them a highly promising electrolyte option. However, the principles governing the selection of diluents, a crucial component in LHCE, have not been clearly determined, hampering the advancement of such a type of electrolyte systems.
View Article and Find Full Text PDFIntermetallic compounds are emerging as promising oxygen reduction reaction (ORR) catalysts for fuel cells due to their typically higher activity and durability compared to disordered alloys. However, the preparation of intermetallic catalysts often requires high-temperature annealing, which unfortunately leads to adverse sintering of the metal nanoparticles. Herein, we develop a scalable site-selective sulfur anchoring strategy that effectively suppresses alloy sintering, ensuring the formation of efficient intermetallic electrocatalysts with small sizes and high ordering degrees.
View Article and Find Full Text PDFDeveloping efficient oxygen evolution reaction (OER) electrocatalysts can greatly advance the commercialization of proton exchange membrane (PEM) water electrolysis. However, the unclear and disputed reaction mechanism and structure-activity relationship of OER pose significant obstacles. Herein, the active site and intermediate for OER on AuIr nanoalloys are simultaneously identified and correlated with the activity, through the integration of in situ shell-isolated nanoparticle-enhanced Raman spectroscopy and X-ray absorption spectroscopy.
View Article and Find Full Text PDFInterfacial water molecules are the most important participants in the hydrogen evolution reaction (HER). Hence, understanding the behavior and role that interfacial water plays will ultimately reveal the HER mechanism. Unfortunately, investigating interfacial water is extremely challenging owing to the interference caused by bulk water molecules and complexity of the interfacial environment.
View Article and Find Full Text PDFis a valuable edible fungus with high nutritional and medicinal values. The mating systems of fungi not only offer practical strategies for breeding, but also have far-reaching effects on genetic variability. has been considered as a sexual species with a tetrapolar mating system based on little experimental data.
View Article and Find Full Text PDFJ Colloid Interface Sci
November 2023
Palladium-based nanocatalysts play an important role in catalyzing the cathode oxygen reduction reaction (ORR) for fuel cells working under alkaline conditions, but the performance still needs to be improved to meet the requirements for large-scale applications. Herein, Au@Pd core-shell nanowires have been developed by coating Pd atomic layers on ultrafine gold nanowires and display outstanding electrocatalytic performance towards alkaline ORR. It is found that Pd overlayers with atomic thickness can be coated on 3 nm Au nanowires under CO atmosphere and completely cover the surfaces.
View Article and Find Full Text PDFSimple and reliable mass production of platinum-based alloy catalysts with excellent activity and stability is an enormous challenge for the wide commercialization of proton-exchange membrane fuel cells (PEMFC), especially those with ultralow loading of Pt. Herein, an economical, highly durable, and efficient catalyst consisting of structurally ordered intermetallic PtCo alloy nanoparticles with ultralow Pt loading (1.4 wt %) supported on hierarchically porous carbon structure (three-dimensional, 3D PtCo/C) were synthesized with large-scale production by the NaCl-template-assisted approach.
View Article and Find Full Text PDFEfficient propagation of spin waves in a magnetically coupled vortex is crucial to the development of future magnonic devices. Thus far, only a double vortex can serve as spin-wave emitter or oscillator; the propagation of spin waves in the higher-order vortex is still lacking. Here, we experimentally realize a higher-order vortex (2D vortex network) by a designed nanostructure, containing four cross-type chiral substructures.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2020
Ni-Mn-based binary oxides are deemed as prospective electrocatalysts for water oxidation. Here, a murdochite-type NiMnO electrocatalyst for water oxidation is reported. Murdochite-type NiMnO with hollow sphere (NMO-HS) and microflower (NMO-MF) structures has been controllably synthesized.
View Article and Find Full Text PDFThe mechanisms of the oxygen reduction reaction (ORR) on Au surfaces are revisited in electrolytes with different pH values by using a combination of electrochemical and in situ surface-enhanced Raman scattering spectroscopy. Surprisingly, the in situ Raman signal of the O-O stretching vibration was detected during the ORR on a Au surface by using a λ=785 nm laser. Both the intermediate products O and H O could be detected, which indicates the difficulty of the further reduction H O and results in a lower electron transfer number, especially in neutral and acid electrolytes.
View Article and Find Full Text PDFThe lithium-sulfur (Li-S) battery is one of the most promising high-energy-density secondary battery systems. However, it suffers from issues arising from its extremely complicated "solid-liquid-solid" reaction routes. In recent years, enormous advances have been made in optimizing Li-S batteries via the rational design of compositions and architectures.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
May 2015
In order to reveal cold hardiness mechanisms and ascertain suitable cold hardiness biochemical indicators of walnut (Juglans regia) , three walnut cultivars ' Hartley' , 'Jinlong 1' and 'Jinlong 2' with strong to weak tolerance of chilling stress, were used to investigate variations of leaf antioxidant enzyme activity and superoxide anion (O2-·) content in one year-old branches under chilling stress at 1 °C in leaf-expansion period. The mesophyll cells ultrastructure of ' Hartley' and 'Jinlong 2' under chilling stress were also observed by transmission electron microscope. The results showed that the superoxide dismutase (SOD) and peroxidase (POD) enzyme activities were the strongest and O2-· content was the lowest in chilling-tolerant cultivar ' Hartley' under chilling stress among the three cultivars.
View Article and Find Full Text PDFZhonghua Liu Xing Bing Xue Za Zhi
September 2011
Objective: To investigate the Cryptosporidium infection and its epidemiological characteristics in HIV/AIDS patients with chronic diarrhea.
Methods: Stool samples collected from HIV/AIDS confirmed patients with chronic diarrhea who lived in Beijing, Henan and Xinjiang. Samples were concentrated by Formalin-Ethyl Acetate Sedimentation technique and stained by modified acid-fast stain (AFS) for the identification of oocysts by microscopy.
This work presents a study of Au conductance quantization based on a combined electrochemical deposition and mechanically controllable break junction (MCBJ) method. We describe the microfabrication process and discuss improved features of our microchip structure compared to the previous one. The improved structure prolongs the available life of the microchip and also increases the success rate of the MCBJ experiment.
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