Ceria–terbia solid solution nanobelts with high catalytic activities for CO oxidation

Ceria–terbia solid solution nanobelts were prepared by an electrochemical route and tested as catalysts of high activity for CO oxidation

(2-Amino­phen­yl)(p-tol­yl)methanone

In the title compound, C14H13NO, the two six-membered rings make a dihedral angle of 52.8 (3)°. An intra­molecular N—H⋯O hydrogen bond involving an amine H atom and the adjacent carbonyl O atom occurs. In the crystal, N—H⋯O and C—H⋯N inter­molecular hydrogen bonds are observed, which may be effective in stabilizing the structure

Homocysteine and Dementia in Parkinson Disease

Parkinson disease (PD) and dementia are neurodegenerative disorders that can be frequently seen in the elderly. Homocysteine (Hcy) is an intermediary metabolite from methylation, which is highly relevant to body physiologic activities including DNA metabolism. Elevated plasma level of homocysteine (eHcy) is seen in normal aging individuals and patients with neurologic disorders such as PD or dementia. Although clinical observations confirm the finding that eHcy is prevalent in PD patients, the former is not a recognized etiology causing PD but rather, an adverse outcome related to the therapy of dopaminergic supplementation. Notably, eHcy may exacerbate various medical and neurologic conditions such as cardiovascular diseases, stroke, mild cognitive impairment, all of which are potential risks for dementia. This chapter discusses the concerns of eHcy relative to dementia in PD

3D‐Printed Graded Electrode with Ultrahigh MnO2 Loading for Non‐Aqueous Electrochemical Energy Storage

Abstract: Electrolytic manganese dioxide is one of the promising cathode candidates for electrochemical energy storage devices due to its high redox capacity and ease of synthesis. Yet, high‐loading MnO2 often suffers from sluggish reaction kinetics, especially in non‐aqueous electrolytes. The non‐uniform deposition of MnO2 on a porous current collectors also makes it difficult to fully utilize the active materials at high mass loading. Here, a 3D printed graded graphene aerogel (3D GA) that contains sparsely separated exterior ligaments is developed to create large open channels for mass transport as well as densely arranged interior ligaments providing large ion‐accessible active surface. The unique structural design homogenizes the thickness of electro deposited MnO2 even at an ultrahigh mass loading of ≈70 mg cm−2. The electrode achieves a remarkable volumetric capacity of 29.1 mA h cm−3 in the non‐aqueous electrolyte. A Li‐ion hybrid capacitor device assembled with a graded 3D GA/MnO2 cathode and graded 3D GA/VOx anode exhibits a wide voltage window of 0–4 V and a superior volumetric energy density of 20.2 W h L−1. The findings offer guidance on 3D printed electrode design for supporting ultrahigh loading of active materials and developments of high energy density energy storage devices

Regulated Interfacial Proton and Water Activity Enhances Mn2+/MnO2 Platform Voltage and Energy Efficiency

Electrolytic MnO2 batteries store charges via the Mn2+/MnO2 two-electron transfer process with higher capacity and voltage than conventional one-electron (Zn2+ or H+) intercalation reactions. Yet, the opposite effect of interfacial H+ on the dissolution/deposition processes and the role of interfacial H2O are rarely discussed. Here we introduce tetrafluoroborate (BF4-) into the sulfate-based electrolyte to regulate interfacial H+ and H2O activity. First, BF4- hydrolysis increases the electrolyte’s acidity, promoting MnO2 dissolution. Second, BF4- forms H-bond networks with interfacial H2O that assist H+ diffusion while retaining a sufficient H2O supply to facilitate MnO2 deposition. As a result, the cathode-free Zn//MnO2 electrolytic cell achieves a high platform of ∼1.92 V and energy efficiency of ∼84.23%. Significantly, the cell delivers 1000 cycles at 1 C with ∼100% Coulombic efficiency and a high energy efficiency retention of 93.65%. Our findings disclose a new strategy to promote Mn2+/MnO2 platform voltage and energy efficiency

Nanocone‐Modified Surface Facilitates Gas Bubble Detachment for High‐Rate Alkaline Water Splitting

Abstract: The significant amount of gas bubbles generated during high‐rate alkaline water splitting (AWS) can be detrimental to the process. The accumulation of bubbles will block the active catalytic sites and hinder the ion and electrolyte diffusion, limiting the maximum current density. Furthermore, the detachment of large bubbles can also damage the electrode's surface layer. Here, a general strategy for facilitating bubble detachment is demonstrated by modifying the nickel electrode surface with nickel nanocone nanostructures, which turns the surface into underwater superaerophobic. Simulation and experimental data show that bubbles take a considerably shorter time to detach from the nanocone‐modified nickel foil than the unmodified foil. As a result, these bubbles also have a smaller detachment size and less chance for bubble coalescence. The nanocone‐modified electrodes, including nickel foil, nickel foam, and 3D‐printed nickel lattice, all show substantially reduced overpotentials at 1000 mA cm−2 compared to their pristine counterpart. The electrolyzer assembled with two nanocone‐modified nickel lattice electrodes retains >95% of the performance after testing at ≈900 mA cm−2 for 100 h. The surface NC structure is also well preserved. The findings offer an exciting and simple strategy for enhancing the bubble detachment and, thus, the electrode activity for high‐rate AWS

The X10 Flare on 2003 October 29: Triggered by Magnetic Reconnection between Counter-Helical Fluxes?

Vector magnetograms taken at Huairou Solar Observing Station (HSOS) and Mees Solar Observatory (MSO) reveal that the super active region (AR) NOAA 10486 was a complex region containing current helicity flux of opposite signs. The main positive sunspots were dominated by negative helicity fields, while positive helicity patches persisted both inside and around the main positive sunspots. Based on a comparison of two days of deduced current helicity density, pronounced changes were noticed which were associated with the occurrence of an X10 flare that peaked at 20:49 UT, 2003 October 29. The average current helicity density (negative) of the main sunspots decreased significantly by about 50. Accordingly, the helicity densities of counter-helical patches (positive) were also found to decay by the same proportion or more. In addition, two hard X-ray (HXR) `footpoints' were observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI} during the flare in the 50-100 keV energy range. The cores of these two HXR footpoints were adjacent to the positions of two patches with positive current helicity which disappeared after the flare. This strongly suggested that the X10 flare on 2003 Oct. 29 resulted from reconnection between magnetic flux tubes having opposite current helicity. Finally, the global decrease of current helicity in AR 10486 by ~50% can be understood as the helicity launched away by the halo coronal mass ejection (CME) associated with the X10 flare.Comment: Solar Physics, 2007, in pres