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Aqueous metal corrosion is a major economic concern in modern society. A phenomenon that has puzzled generations of scientists in this field is the so-called anomalous hydrogen evolution: the violent dissolution of magnesium under electron-deficient (anodic) conditions, accompanied by strong hydrogen evolution and a key mechanism hampering Mg technology. Experimental studies have indicated the presence of univalent Mg + in solution, but these findings have been largely ignored because they defy our common chemical understanding and evaded direct experimental observation. Using recent advances in the ab initio description of solid-liquid electrochemical interfaces under controlled potential conditions, we describe the full reaction path of Mg atom dissolution from a kinked Mg surface under anodic conditions. Our study reveals the formation of a solvated [Mg 2+ (OH) - ] + ion complex, challenging the conventional assumption of Mg 2+ ion formation. This insight provides an intuitive explanation for the postulated presence of (Coulombically) univalent Mg + ions, and the absence of protective oxide/hydroxide layers normally formed under anodic/oxidizing conditions. The discovery of this unexpected and unconventional reaction mechanism is crucial for identifying new strategies for corrosion prevention and can be transferred to other metals.

We discuss how to include our recently proposed thermopotentiostat technique [Deissenbeck et al. Phys. Rev. Lett. 2021, 126, 136803] into any existing ab initio molecular dynamics (AIMD) package. Using thermopotentiostat AIMD simulations in the canonical NVTΦ ensemble at a constant electrode potential, we compute the polarization bound charge and dielectric response of interfacial water from first principles.

Control over microstructure and interparticle spacing in substrate-supported colloidal arrangements is a key challenge in colloidal self-assembly. We demonstrate here the preparation of Moiré and honeycomb monolayer lattices from core/shell microgels with rigid inorganic cores and soft, deformable hydrogel shells. These structures were realized by the sequential double deposition of freely floating monolayers from the air/water interface onto the same, centimetre-scale substrate. Due to the soft and deformable character of the hydrogel shells, the second applied monolayer fully settles into the same plane as the first monolayer. The resulting structural motif is determined by the drying conditions applied to the second deposition step. We support our experimental findings by Brownian dynamics simulations and provide insights into the structure formation process.

We investigate the ground state of a classical two-dimensional system of hard-sphere dipoles confined between two hard walls. Using lattice sum minimization techniques we reveal that at fixed wall separations, a first-order transition from a vacuum to a straight one-dimensional chain of dipoles occurs upon increasing the density. Further increase in the density yields the stability of an undulated chain as well as nontrivial buckling structures. We explore the close-packed configurations of dipoles in detail, and we find that, in general, the densest packings of dipoles possess complex magnetizations along the principal axis of the slit. Our predictions serve as a guideline for experiments with granular dipolar and magnetic colloidal suspensions confined in slitlike channel geometry.