Computational Study on the Octahedral Surfaces of Magnetite Nanoparticles and Their Solvent Interaction.

Magnetite nanoparticles (MNPs) play an important role in geological and environmental systems because of their redox reactivity and ability to sequester a wide range of metals and metalloids. X-ray absorption spectroscopy conducted at metal and metalloid edges has suggested that the magnetite {111} faces of octahedrally shaped nanoparticles play a dominant role in the redox and sorption processes of these elements. However, studies directly probing the magnetite surfaces, especially in their fully solvated state, are scarce.

Diels-Alder Network Blends as Self-Healing Encapsulants for Liquid Metal-Based Stretchable Electronics.

Two dynamic covalent networks based on the Diels-Alder reaction were blended to exploit the properties of the dissimilar polymer backbones. Furan-functionalized polyether amines based on poly(propylene oxide) (PPO) FD4000 and polydimethylsiloxane (PDMS) FS5000 were mixed in a common solvent and reversibly cross-linked with the same bismaleimide DPBM. The morphology of the phase-separated blends is primarily controlled by the concentration of backbones.

Cobalt-free layered perovskites RBaCuFeO (R = 4f lanthanide) as electrocatalysts for the oxygen evolution reaction.

Co-based perovskite oxides are intensively studied as promising catalysts for electrochemical water splitting in an alkaline environment. However, the increasing Co demand by the battery industry is pushing the search for Co-free alternatives. Here we report a systematic study of the Co-free layered perovskite famil RBaCuFeO (R = 4f lanthanide), where we uncover the existence of clear correlations between electrochemical properties and several physicochemical descriptors.

Stability and Speciation of Hydrated Magnetite {111} Surfaces from Ab Initio Simulations with Relevance for Geochemical Redox Processes.

Magnetite is a common mixed Fe(II,III) iron oxide in mineral deposits and the product of (anaerobic) iron corrosion. In various Earth systems, magnetite surfaces participate in surface-mediated redox reactions. The reactivity and redox properties of the magnetite surface depend on the surface speciation, which varies with environmental conditions.

Dynamically disordered hydrogen bonds in the hureaulite-type phosphatic oxyhydroxide Mn[(PO)(PO(OH))](HOH).

We report the temperature evolution of hydrogen bond (HB) chains and rings in Mn[(PO)(PO(OH))](HOH) to reveal conduction pathways based on difference Fourier maps with neutron- and synchrotron x-ray diffraction data. Localized proton dynamics for the five distinct hydrogen sites were observed and identified in this study. Their temperature evaluation over ten orders of magnitude in time was followed by means of quasielastic neutron scattering, dielectric spectroscopy, and ab initio molecular dynamics.