Silicene, germanene and stanene likely to graphene are atomic thick material with interesting properties. We employed first-principles density functional theory (DFT) calculations to investigate and compare the interaction of Na or Li ions on these films. We first identified the most stable binding sites and their corresponding binding energies for a single Na or Li adatom on the considered membranes. Then we gradually increased the ions concentration until the full saturation of the surfaces is achieved. Our Bader charge analysis confirmed complete charge transfer between Li or Na ions with the studied 2D sheets. We then utilized nudged elastic band method to analyze and compare the energy barriers for Li or Na ions diffusions along the surface and through the films thicknesses. Our investigation findings can be useful for the potential application of silicene, germanene and stanene for Na or Li ion batteries.

Chirality-induced spin selectivity (CISS) is a recently discovered effect, whose precise microscopic origin has not yet been fully elucidated; it seems, however, clear that spin-orbit interaction plays a pivotal role. Various model Hamiltonian approaches have been proposed, suggesting a close connection between spin selectivity and filtering and helical symmetry. However, first-principles studies revealing the influence of chirality on the spin polarization are missing. To clearly demonstrate the influence of the helical conformation on the spin polarization properties, we have carried out spin-dependent Density-Functional Theory (DFT) based transport calculations for a model molecular system. It consists of α-helix and β-strand conformations of an oligo-glycine peptide, which is bonded to a nickel electrode and to a gold electrode in a two-terminal setup, similar to a molecular junction or a local probe, for example, in STM or AFM configurations. We have found that the α-helix conformation displays a spin polarization, calculated through the intrinsic magneto-resistance of the junction, about 100-1000 times larger than the linear β-strand, clearly demonstrating the crucial role played by the molecular helical geometry on the enhancement of spin polarization associated with the CISS effect.

Borophene, the boron atom analogue to graphene, being atomic thick have been just recently experimentally fabricated. In this work, we employ first-principles density functional theory calculations to investigate the interaction of Ca, Mg, Na or Li atoms with single-layer and free-standing borophene. We first identified the most stable binding sites and their corresponding binding energies as well and then we gradually increased the ions concentration. Our calculations predict strong binding energies of around 4.03 eV, 2.09 eV, 2.92 eV and 3.28 eV between the borophene substrate and Ca, Mg, Na or Li ions, respectively. We found that the binding energy generally decreases by increasing the ions content. Using the Bader charge analysis, we evaluate the charge transfer between the adatoms and the borophene sheet. Our investigation proposes the borophene as a 2D material with a remarkably high capacity of around 800 mAh/g, 1960 mAh/g, 1380 mAh/g and 1720 mAh/g for Ca, Mg, Na or Li ions storage, respectively. This study can be useful for the possible application of borophene for the rechargeable ion batteries.

There is increasing interest in the study of chiral degrees of freedom occurring in matter and in electromagnetic fields. Opportunities in quantum sciences will likely exploit two main areas that are the focus of this Review: (1) recent observations of the chiral-induced spin selectivity (CISS) effect in chiral molecules and engineered nanomaterials and (2) rapidly evolving nanophotonic strategies designed to amplify chiral light–matter interactions. On the one hand, the CISS effect underpins the observation that charge transport through nanoscopic chiral structures favors a particular electronic spin orientation, resulting in large room-temperature spin polarizations. Observations of the CISS effect suggest opportunities for spin control and for the design and fabrication of room-temperature quantum devices from the bottom up, with atomic-scale precision and molecular modularity. On the other hand, chiral–optical effects that depend on both spin- and orbital-angular momentum of photons could offer key advantages in all-optical and quantum information technologies. In particular, amplification of these chiral light–matter interactions using rationally designed plasmonic and dielectric nanomaterials provide approaches to manipulate light intensity, polarization, and phase in confined nanoscale geometries. Any technology that relies on optimal charge transport, or optical control and readout, including quantum devices for logic, sensing, and storage, may benefit from chiral quantum properties. These properties can be theoretically and experimentally investigated from a quantum information perspective, which has not yet been fully developed. There are uncharted implications for the quantum sciences once chiral couplings can be engineered to control the storage, transduction, and manipulation of quantum information. This forward-looking Review provides a survey of the experimental and theoretical fundamentals of chiral-influenced quantum effects and presents a vision for their possible future roles in enabling room-temperature quantum technologies.

In this work, we demonstrate the first synthesis of vinylene‐linked 2D CPs, namely, 2D poly(phenylenequinoxalinevinylene)s 2D‐PPQV1 and 2D‐PPQV2, via the Horner–Wadsworth–Emmons (HWE) reaction of C2‐symmetric 1,4‐bis(diethylphosphonomethyl)benzene or 4,4′‐bis(diethylphosphonomethyl)biphenyl with C3‐symmetric 2,3,8,9,14,15‐hexa(4‐formylphenyl)diquinoxalino[2,3‐a:2′,3′‐c]phenazine as monomers. Density functional theory (DFT) simulations unveil the crucial role of the initial reversible C−C single bond formation for the synthesis of crystalline 2D CPs. Powder X‐ray diffraction (PXRD) studies and nitrogen adsorption‐desorption measurements demonstrate the formation of proclaimed crystalline, dual‐pore structures with surface areas of up to 440 m2 g−1. More importantly, the optoelectronic properties of the obtained 2D‐PPQV1 (Eg=2.2 eV) and 2D‐PPQV2 (Eg=2.2 eV) are compared with those of cyano‐vinylene‐linked 2D‐CN‐PPQV1 (Eg=2.4 eV) produced by the Knoevenagel reaction and imine‐linked 2D COF analog (2D‐C=N‐PPQV1, Eg=2.3 eV), unambiguously proving the superior conjugation of the vinylene‐linked 2D CPs using the HWE reaction.

Recent experimental advances for the fabrication of various borophene sheets introduced new structures with a wide prospect of applications. Borophene is the boron atoms analogue of graphene. Borophene exhibits various structural polymorphs all of which are metallic. In this work, we employed first-principles density functional theory calculations to investigate the mechanical properties of five different singlelayer borophene sheets. In particular, we analyzed the effect of loading direction and point vacancy on the mechanical response of borophene. Moreover, we compared the thermal stabilities of the considered borophene systems. Based on the results of our modelling, borophene films depending on the atomic configurations and the loading direction can yield remarkable elastic modulus in the range of 163-382 GPa.nm and high ultimate tensile strength from 13.5 GPa.nm to around 22.8 GPa.nm at the corresponding strain from 0.1 to 0.21. Our study reveals the remarkable mechanical characteristics of borophene films.

A new class of multimetallic hierarchical aerogels composed entirely of interconnected Ni-Pd Pt nano-building-blocks with in situ engineered morphologies and compositions is demonstrated. The underlying mechanism of the galvanic shape-engineering is elucidated in terms of nanowelding of intermediate nanoparticles. The hierarchical aerogels integrate two levels of porous structures, leading to improved electrocatalysis performance.

A recent scanning tunneling microscopy study by Mitsui et al. [Nature (London) 422, 705 (2003)] challenged the well-accepted picture based on early studies of Langmuir that an ensemble of at least two empty, catalytically active sites is required for the dissociative adsorption; instead, aggregates of three or more vacancies should be necessary. We have performed the first ab initio molecular dynamics study of the adsorption dynamics on a precovered surface providing detailed insights into the coverage dependence of the adsorption probability. The simulations show that there is no need to refine the Langmuirian picture: A dimer vacancy is still sufficient to dissociate hydrogen provided the kinetic energy of the molecules is large enough to overcome the relatively small adsorption barrier. In addition, we elucidate further aspects of the dissociation dynamics at precovered surfaces.