Perspective of material evolution Induced by sinusoidal reflex charging in lithium-ion batteries.

Background: Lithium-ion batteries are globally prominent and extensively employed alternative energy sources with decisive applications. In depth understanding of influences of various charging and discharging cycles on electrode materials and life span of these batteries is critical as cycle-life and safety of lithium-ion batteries are closely related crystallinity of electrode materials. This study is a detailed investigation endeavor in observing the degree of damage to electrode materials under multiple charging and discharging cycles.

Bifunctional Monolayer WSe/Graphene Self-Stitching Heterojunction Microreactors for Efficient Overall Water Splitting in Neutral Medium.

Developing efficient bifunctional electrocatalysts in neutral media to avoid the deterioration of electrodes or catalysts under harsh environments has become the ultimate goal in electrochemical water splitting. This work demonstrates the fabrication of an on-chip bifunctional two-dimensional (2D) monolayer (ML) WSe/graphene heterojunction microreactor for efficient overall water splitting in a neutral medium (pH = 7). Through the synergistic atomic growth of the metallic Cr dopant and graphene stitching contact on the 2D ML WSe, the bifunctional WSe/graphene heterojunction microreactor consisting of a full-cell configuration demonstrates excellent performance for overall water splitting in a neutral medium.

Irradiation-Induced Synthesis of Ag/ZnO Nanostructures as Surface-Enhanced Raman Scattering Sensors for Sensitive Detection of the Pesticide Acetamiprid.

Detecting pesticides using techniques that involve simple fabrication methods and conducting the detection at very low levels are challenging. Herein, we report the detection of acetamiprid at the quadrillionth level using surface-enhanced Raman scattering (SERS). The SERS chip comprises Ag nanoparticles deposited on a tetrapod structure of ZnO coated onto indium tin oxide glass (denoted as Ag@ZnO-ITO).

Corrosion Resistance and Thermal Conductivity Enhancement of Reduced Graphene Oxide-BaSO-Epoxy Composites.

The results of studies on the corrosion protectiveness and thermal conductivity of reduced graphene oxide-BaSO epoxy composites are reported here. A commercial epoxy resin and reduced graphene oxide (rGO) were blended with a hardening reagent and then mixed with prepared BaSO-epoxy resin (B-epoxy). The reduced graphene oxide-BaSO-epoxy composite (rGO-B-epoxy) paste was used to coat the surfaces of Al 7205 alloy and the corrosion and thermal properties were investigated.

Oxidation Behavior Characterization of Zircaloy-4 Cladding with Different Hydrogen Concentrations at 500-800 °C in an Ambient Atmosphere.

This study simulated the after-burned zirconium cladding oxidation in air at temperatures between 500 and 800 °C. The weight changes of Zircaloy-4 cladding with hydrogen contents of 100-1000 ppm continuously measured through thermogravimetric analysis (TGA) during oxidation tests at different temperatures in an air atmosphere. The TGA results indicate a transition of oxidation kinetics from a parabolic rate law to a linear rate law for as-received and hydrided Zircaloy-4 cladding.

Direct investigation of the reorientational dynamics of A-site cations in 2D organic-inorganic hybrid perovskite by solid-state NMR.

Limited methods are available for investigating the reorientational dynamics of A-site cations in two-dimensional organic-inorganic hybrid perovskites (2D OIHPs), which play a pivotal role in determining their physical properties. Here, we describe an approach to study the dynamics of A-site cations using solid-state NMR and stable isotope labelling. H NMR of 2D OIHPs incorporating methyl-d-ammonium cations (d-MA) reveals the existence of multiple modes of reorientational motions of MA.

Surface Structure Analysis of Initial High-Temperature Oxidation of SS441 Stainless Steel.

Chromia-forming ferritic stainless steel (FSS) is a highly promising interconnect material for application in solid oxide fuel cells. In this study, initial oxidation of chromium oxides was performed at 500-800 °C to understand the evolution of materials at an early stage. The structural variations in oxide scales were analyzed through scanning electron microscopy, energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), X-ray diffractometry (XRD), laser confocal microscopy (LSCM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy.

Probing the active site in single-atom oxygen reduction catalysts via operando X-ray and electrochemical spectroscopy.

Nonnoble metal catalysts are low-cost alternatives to Pt for the oxygen reduction reactions (ORRs), which have been studied for various applications in electrocatalytic systems. Among them, transition metal complexes, characterized by a redox-active single-metal-atom with biomimetic ligands, such as pyrolyzed cobalt-nitrogen-carbon (Co-N/C), have attracted considerable attention. Therefore, we reported the ORR mechanism of pyrolyzed Vitamin B12 using operando X-ray absorption spectroscopy coupled with electrochemical impedance spectroscopy, which enables operando monitoring of the oxygen binding site on the metal center.

Electrochemical polarization analysis for optimization of external operation parameters in zinc fuel cells.

Zinc-air flow fuel cells utilizing zinc particles as fuel possess the potential to evolve as efficient distributed grid generators. In this research study, electrochemical impedance analysis was employed to determine the optimum design and operational parameters for the feasible maneuver and enhanced energy generation from zinc fuel cells. Polarization resistance ( ), ohmic resistance ( ), and mass transfer resistance ( ) were used as the indicators for determination of the optimum parameters of fuel cell performance.

Characterization of Au and Bimetallic PtAu Nanoparticles on PDDA-Graphene Sheets as Electrocatalysts for Formic Acid Oxidation.

Nanocomposite materials of the Au nanoparticles (Au/PDDA-G) and the bimetallic PtAu nanoparticles on poly-(diallyldimethylammonium chloride) (PDDA)-modified graphene sheets (PtAu/PDDA-G) were prepared with hydrothermal method at 90 °C for 24 h. The composite materials Au/PDDA-G and PtAu/PDDA-G were evaluated by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA) for exploring the structural characterization for the electrochemical catalysis. According to TEM results, the diameter of Au and bimetallic PtAu nanoparticles is about 20-50 and 5-10 nm, respectively.

Synthesis and characterizations of Ni-NiO nanoparticles on PDDA-modified graphene for oxygen reduction reaction.

We are presenting our recent research results about the Ni-NiO nanoparticles on poly-(diallyldimethylammonium chloride)-modified graphene sheet (Ni-NiO/PDDA-G) nanocomposites prepared by the hydrothermal method at 90°C for 24 h. The Ni-NiO nanoparticles on PDDA-modified graphene sheets are measured by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and selected area electron diffraction (SAED) pattern for exploring the structural evidence to apply in the electrochemical catalysts. The size of Ni-NiO nanoparticles is around 5 nm based on TEM observations.

Autocatalytic reaction in hydrolysis of difructose anhydride III.

Hydrolysis of several polysaccharides in neutral and weak acid environment has been shown to exhibit autocatalytic behavior. Because the pH value of the solution decreases during hydrolysis, it has been proposed that proton is the catalyst of the autocatalytic reaction. We monitored the hydrolysis of difructose anhydride III (DFA III) in both strong and weak acid environment using Raman spectroscopy and found that it is also an autocatalytic reaction.

Barrierless proton transfer within short protonated peptides in the presence of water bridges. A density functional theory study.

We have used density functional theory at the B3LYP/6-31++G(d,p) level of theory to investigate proton transfer in protonated N(2)-acetyl-N(1)-methylglycinamide and N-acetylglycyl-N(1)-methylglycinamide with multiwater assistance and to determine the structures and energies of the most important minima and transition states corresponding to the proton-transfer pathways. We propose mechanisms for proton transfer between adjacent and nonadjacent carbonyl oxygen atoms with water bridge assistance. The presence of a two-water bridge connected to the two carbonyl oxygen atoms provides a proton-transfer mechanism having such a low-barrier that the excess proton is almost freely mobile.