Theoretical Investigation of Two-Dimensional FeC Structures with Surface Van Hove Singularity for Electrochemical Nitric Oxide Reduction Reaction.

The electrochemical nitric oxide reduction reaction (eNORR) is an efficient method for converting aqueous NO into NH. The pursuit of innovative electrocatalysts with enhanced activity, selectivity, durability, and cost-effectiveness for NORR remains a research focus. In this study, using particle swarm optimization (PSO) searches, density functional theory (DFT), and the constant-potential method (CPM), we predict two stable two-dimensional FeC monolayers, designated as α-FeC and β-FeC, as promising electrocatalysts for the NORR.

Computational discovery of two-dimensional tetragonal group IV-V monolayers.

The two-dimensional (2D) hexagonal group IV-V family has attracted significant attention due to their unique properties and potential applications in electronics, spintronics, and photocatalysis. In this study, we report the discovery of a stable tetragonal allotrope, termed the Td4 phase, of 2D IV-V monolayers through a structural search utilizing an adaptive genetic algorithm. We investigate the geometric structures, structural stabilities, and band structures of the Td4-phase 2D IV-V monolayers (where IV = Si, Ge, Sn; V = P, As, Sb) based on the first-principles calculations.

2D-MnC: An Optimal Electrocatalyst with Nonbonding Multiple Single Centers for CO-to-CH Conversion.

The CO reduction reaction (CORR) is a promising method that can both mitigate the greenhouse effect and generate valuable chemicals. The 2D-MC with high-density transition metal single atoms is a potential catalyst for various catalytic reactions. Using an effective strategy, we screened 1s-MnC as the most promising electrocatalyst for the CORR in the newly reported 2D-MC family.

Influence of Zr aggregation on Li-ion conductivity of amorphous solid-state electrolyte Li-La-Zr-O.

In our study, we investigated the influence of the local structure of amorphous Li-La-Zr-O (a-LLZO) on Li-ion conductivity using ab initio molecular dynamics (AIMD). A-LLZO has shown promising properties in inhibiting the growth of lithium dendrites, making it a potential candidate for solid electrolytes in all-solid-state lithium batteries. The low Li-ion conductivity of a-LLZO is currently limiting its practical applications.

First-Principles Studies on the Structural and Electronic Properties of α-NaFePOF with Strong Antisite Disorder.

Polyanionic NaFePOF is one of the most important cathode materials for sodium-ion batteries. The orthorhombic β-NaFePOF material has been studied extensively and intensively since it was proposed. In this article, a novel monoclinic sodium phosphate fluoride α-NaFePOF is concerned.

Generating waxy rice starch with target type of amylopectin fine structure and gelatinization temperature by waxy gene editing.

Waxy rice, which lacks amylose, is an important variant in rice, and its starches have been widely used. New waxy rice varieties generated via the CRISPR/Cas9 gene-editing system is described. Herein, four waxy rice starches with different physicochemical properties were successfully obtained by the CRISPR/Cas9 editing Waxy (Wx) gene.

In Situ Induced Lattice-Matched Interfacial Oxygen-Passivation-Layer Endowing Li-Rich and Mn-Based Cathodes with Ultralong Life.

The high capacity of Li-rich and Mn-based (LRM) cathode materials is originally due to the unique hybrid anion- and cation redox, which also induces detrimental oxygen escape. Furthermore, the counter diffusion of released oxygen (into electrolyte) and induced oxygen vacancies (into the interior bulk phase) that occurs at the interface will cause uncontrolled phase collapse and other issues. Therefore, due to its higher working voltage (>4.

Assessment of the Characteristics of Waxy Rice Mutants Generated by CRISPR/Cas9.

The cooking and eating quality of rice grains is a major focus from a consumer's perspective and is mainly determined by the apparent amylose content (AAC) of the starch. Waxy rice, a type of rice with an AAC of less than 2%, is an important goal for the breeding of high-quality rice. In recent years, the cloning of the ( gene has revealed the molecular mechanism of the formation of waxy traits in rice.

Quantum spin Hall effect in tilted penta silicene and its isoelectronic substitutions.

Silicene, a competitive two-dimensional (2D) material for future electronic devices, has attracted intensive attention in condensed matter physics. Utilizing an adaptive genetic algorithm (AGA), we identify a topological allotrope of silicene, named tilted penta () silicene. Based on first-principles calculations, the geometric and electronic properties of silicene and its isoelectronic substitutions (Ge, Sn) are investigated.

Charge Compensation Mechanisms and Oxygen Vacancy Formations in LiNiCoMnO: First-Principles Calculations.

Charge compensation mechanisms in the delithiation processes of LiNiCoMnO (NCM111) are compared in detail by the first-principles calculations with GGA and GGA+ methods under different values reported in the literature. The calculations suggested that different sets of values lead to different charge compensation mechanisms in the delithiation process. Co/Co couples were shown to dominate the redox reaction for 1 ≥ ≥ 2/3 by using the GGA+ method ( = 6.

Luminescence and energy transfer of warm white-emitting phosphor MgYAlSiO:Dy,Eu for white LEDs.

A series of MgYAlSiO:Dy,Eu phosphors were synthesized by the solid-state method. The luminescent properties and crystal structures of the MgYAlSiO:Dy,Eu phosphors were analyzed. The XRD results show that the synthesized MgYAlSiO:Dy,Eu phosphors are of pure phase.

Formation of oxygen vacancies in LiFeSiO: first-principles calculations.

The formation of oxygen vacancies could affect various properties of oxides. Herein we have investigated the formation energies of an oxygen vacancy (V) with the relevant charge states in bulk -LiFeSiO using first-principles calculations. The formation energies of the V are essentially dependent on the atomic chemical potentials that represent the experimental conditions.

First-Principles Observation of Bonded 2D BC Bilayers.

Two-dimensional (2D) B-C compounds possess rich allotropic structures with many applications. Obtaining new 2D BC structures is highly desirable due to the novel applications of three-dimensional (3D) BC in protections. In this work, we proposed a new family of 2D BC from the first-principles calculations.

Significant second-harmonic generation and bulk photovoltaic effect in trigonal selenium and tellurium chains.

One-dimensional (1D) selenium and tellurium crystalize in helical chainlike structures and thus exhibit fascinating properties. By performing first-principles calculations, we have researched the linear and nonlinear optical (NLO) properties of 1D Se and Te, and find that both systems exhibit pronounced NLO responses. In particular, 1D Se is found to possess a large second-harmonic generation coefficient with the χ value being up to 7 times larger than that of GaN, and is even several times larger than that of the bulk counterpart.

Identifying a Li-rich superionic conductor from charge-discharge structural evolution study: LiMnO.

LiMnO is a critical member of the Li-rich Mn-based layered material. To understand the process of electrochemical reaction in the monoclinic LiMnO, the structural evolution is investigated through the first-principles calculations based on density functional theory. During the delithiation process, a phase transformation together with a new trigonal phase at x = 0.

Anionic Redox Processes in Maricite- and Triphylite-NaFePO of Sodium-Ion Batteries.

In recent years, NaFePO has been regarded as one of the most promising cathode materials for next-generation rechargeable sodium-ion batteries. There is significant interest in the redox processes of rechargeable batteries for high capacity applications. In this paper, the redox processes of triphylite-NaFePO and maricite-NaFePO materials have been analyzed based on first-principles calculations and analysis of Bader charges.

Manipulating External Electric Field and Tensile Strain toward High Energy Density Stability in Fast-Charging Li-Rich Cathode Materials.

Li-rich layered oxides (LLOs) are promising cathodes for lithium-ion batteries because of their high energy density provided by anionic redox. Although great improvements have been achieved in electrochemical performance, little attention has been paid to the energy density stability during fast charging. Indeed, LLOs have severe capacity fading and voltage decay especially at a high state of charge (SOC), disabling the application of the frequently used constant-current-constant-voltage mode for fast charging.

HOT Graphene and HOT Graphene Nanotubes: New Low Dimensional Semimetals and Semiconductors.

We report a new graphene allotrope named HOT graphene containing carbon hexagons, octagons, and tetragons. A corresponding series of nanotubes are also constructed by rolling up the HOT graphene sheet. Ab initio calculations are performed on geometric and electronic structures of the HOT graphene and the HOT graphene nanotubes.

Comparative study on the electronic structures and redox reactions in LiCrX and NaCrX (X = O and S).

LiCrO and NaCrO have been well-studied as cathode materials in lithium and sodium ion batteries, while the studies on LiCrS and NaCrS are relatively rare. In this work, a comparative study on the electronic structures and redox reactions in oxides (LiCrO, NaCrO) and sulfides (LiCrS, NaCrS) is performed. A first-principles method has been used to calculate the Bader charge transfer, the electronic structures and the magnetic moments during the entire delithiation or desodiation process.

Dependence of Electronic and Optical Properties of MoS Multilayers on the Interlayer Coupling and Van Hove Singularity.

In this paper, the structural, electronic, and optical properties of MoS multilayers are investigated by employing the first-principles method. Up to six-layers of MoS have been comparatively studied. The covalency and ionicity in the MoS monolayer are shown to be stronger than those in the bulk.

Lithium Deficiencies Engineering in Li-Rich Layered Oxide LiMnNiCoO for High-Stability Cathode.

Li-rich layered oxides have been in focus because of their high specific capacity. However, they usually suffer from poor kinetics, severe voltage decay, and capacity fading. Herein, a long-neglected Li-deficient method is demonstrated to address these problems by simply reducing the lithium content.

A Guideline for Tailoring Lattice Oxygen Activity in Lithium-Rich Layered Cathodes by Strain.

Lattice oxygen activity plays a dominant role in balancing discharge capacity and performance decay of lithium-rich layered oxide cathodes (LLOs). On the basis of density functional theory (DFT) and tight-binding theory, the activity of lattice oxygen can be improved by tensile strain and suppressed by compressive strain. To verify this conclusion, LLOs with large lattice parameters (L-LLOs) were synthesized taking advantage of the lattice expansion effect in nanomaterials.

Electronic Properties of Vanadium Atoms Adsorption on Clean and Graphene-Covered Cu(111) Surface.

The electronic properties of vanadium atoms adsorbed on clean and graphene-covered Cu(111) surface have been systematically studied using ab initio theoretical method. Two coverages (1/9 ML and 1 ML) of vanadium adsorption are considered in this work. Our calculations indicate that V staying underneath the Cu surface is found to be the most stable adsorption site at the aforementioned two coverages for V/Cu(111).

Fe-Si networks and charge/discharge-induced phase transitions in LiFeSiO cathode materials.

Structural phase transitions of electrode materials are responsible for poor reversibility during charge/discharge cycling in Li-ion batteries. Using previously developed structural databases, we investigate a structural landscape for LixFeSiO4 systems at x = 1. Starting with low-energy Li2FeSiO4 crystal structures, we explore the crystal structures of the material in different states of charge.