Nacre-Inspired Nanocomposites from Natural Polypeptide ε-Poly-l-Lysine and Natural Clay Montmorillonite: Remarkable Reinforcing Effect at Low Polymer Content and Its Mechanism.

Nanocomposites composed of the cationic polypeptide ε-poly-l-lysine (ε-PL) and natural sodium montmorillonite (MMT) were prepared and evaluated. These MMT/ε-PL composites formed highly ordered nanostructures resembling natural nacreous layers by a simple process. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses confirmed that a small amount of ε-PL remarkably enhanced the MMT orientation in the composites.

Thermal Stability of High-Entropy Alloy Nanoparticles Evaluated by In Situ TEM Observations.

High-entropy alloy (HEA) nanoparticles (NPs) have attracted attention in several fields because of their fascinating properties. The high mechanical strength, good thermal stability, and superior corrosion resistance of HEAs, which are derived from their high configurational entropy, are attractive features. Herein, we investigated the thermal stability of FeCoNiCuPd HEA NPs on reduced graphene oxide via in situ transmission electron microscopy observations at elevated temperatures.

Sub-nanometric High-Entropy Alloy Cluster: Hydrogen Spillover Driven Synthesis on CeO and Structural Reversibility.

High-entropy alloy (HEA) nanoparticles (NPs) have attracted significant attention as promising catalysts owing to the various unique synergistic effects originating from the nanometer-scale, near-equimolar mixing of five or more components to produce single-phase solid solutions. However, the study of sub-nanometer HEA clusters having sizes of less than 1 nm remains incomplete despite the possibility of novel functions related to borderline molecular states with discrete quantum energy levels. The present work demonstrates the synthesis of CeO nanorods (CeO-NRs) on which sub-nanometer CoNiCuZnPd HEA clusters were formed with the aid of a pronounced hydrogen spillover effect on readily reducible CeO (110) facets.

Hydrogen spillover-driven synthesis of high-entropy alloy nanoparticles as a robust catalyst for CO hydrogenation.

High-entropy alloys (HEAs) have been intensively pursued as potentially advanced materials because of their exceptional properties. However, the facile fabrication of nanometer-sized HEAs over conventional catalyst supports remains challenging, and the design of rational synthetic protocols would permit the development of innovative catalysts with a wide range of potential compositions. Herein, we demonstrate that titanium dioxide (TiO) is a promising platform for the low-temperature synthesis of supported CoNiCuRuPd HEA nanoparticles (NPs) at 400 °C.

Enhancement of CO adsorption on biochar sorbent modified by metal incorporation.

This work is scrutinizing the development of metallized biochar as a low-cost bio-sorbent for low temperature CO capture with high adsorption capacity. Accordingly, single-step pyrolysis process was carried out in order to synthesize biochar from rambutan peel (RP) at different temperatures. The biochar product was then subjected to wet impregnation with several magnesium salts including magnesium nitrate, magnesium sulphate, magnesium chloride and magnesium acetate which then subsequently heat-treated with N.

Self-activated surface dynamics in gold catalysts under reaction environments.

Nanoporous gold (NPG) with sponge-like structures has been studied by atomic-scale and microsecond-resolution environmental transmission electron microscopy (ETEM) combined with ab initio energy calculations. Peculiar surface dynamics were found in the reaction environment for the oxidation of CO at room temperature, involving residual silver in the NPG leaves as well as gold and oxygen atoms, especially on {110} facets. The NPG is thus classified as a novel self-activating catalyst.

Detecting dynamic responses of materials and devices under an alternating electric potential by phase-locked transmission electron microscopy.

An apparatus is developed for transmission electron microscopy (TEM) to acquire image and spectral data, such as TEM images, electron holograms, and electron energy loss spectra, synchronized with the measurement of the dynamic response of a specimen under an applied alternating current (AC) electric potential (voltage, denoted V). From a V of frequency f, a shutter pulse signal is generated to open and close a pre-specimen shutter in a base TEM apparatus. A pulse is generated per V cycle from the targeted phase Φ to Φ +∆Φ with phase width ∆Φ (∆Φ <2π).

Revealing the heterogeneous contamination process in metal nanoparticulate catalysts in CO gas without purification by in situ environmental transmission electron microscopy.

It is known that samples become contaminated in CO gas of high pressure unless care is taken with the gas supply line to an environmental transmission electron microscope. This technical note reveals the heterogeneous formation process of contamination in situ on a nanoparticulate catalyst sample. It is shown that the surface of metal nanoparticles is preferentially contaminated, while the surface of metal oxide supports remains uncontaminated.