Nitrogen substitution induced lattice contraction in nickel nanoparticles for electrochemical hydrogen evolution from simulated seawater.

Herein, we demonstrate a facile method for the introduction of nitrogen in the lattices of nickel nanoparticles to form NiN ( = 0.13, 0.20, 0.

Site dependent catalytic water dissociation on an anisotropic buckled black phosphorus surface.

Black phosphorus (BP) is unique among 2D materials due to its anisotropic puckered structure. It has been used as a multifunctional catalyst for various purposes. In this study, we performed first principles molecular dynamics simulations to understand the water-splitting reaction on a bi-layer BP surface.

Amphiphilicity of Intricate Layered Graphene/g-CN Nanosheets.

The hybrid heterostructure of the tri--triazine form of graphitic carbon nitride (g-CN), a stable two-dimensional material, results from intricate layer formation with graphene. In this material, g-CN, an amphiphilic material, stabilizes Pickering emulsions as an emulsifier and can effectively disperse graphene. Due to the various technological applications of the hybrid nanosheets in an aqueous environment, it is essential to study the interaction of water molecules with graphene and g-CN (Gr/g-CN)-combined heterostructure.

Aqueous Affinity and Interfacial Dynamics of Anisotropic Buckled Black Phosphorous.

The structure of black phosphorous (BP) is similar to the honeycomb arrangement of graphene, but the layered BP is found to be buckled and highly anisotropic. The buckled surface structure affects interfacial molecule mobility and plays a vital role in various nanomaterial applications. The BP is also known for wettability, droplet formation, stability, and hydrophobicity in the aqueous environment.

Comparative first principles-based molecular dynamics study of catalytic mechanism and reaction energetics of water oxidation reaction on 2D-surface.

The study of the water-splitting process, which can proceed in 2e as well as 4e pathway, reveals that the process is entirely an uphill process, and the third step, that is, the oxooxo bond formation is the rate-determining step. The kinetic barrier of the oxygen evolution reaction (OER) on the 2D material catalysts in the presence of explicit solvents is scarcely studied. Here, we investigate the dynamics of the OER on the undoped graphene and the activation energy barrier of each step using first principles molecular dynamics simulations.

Insignificant Effect of Temperature on the Structure and Angular Jumps of Water near a Hydrophobic Cation.

The ambiguity in the behavior of water molecules around hydrophobic solutes is a matter of interest for many studies. Motivated by the earlier results on the dynamics of water molecules around tetramethylammonium (TMA) cation, we present the effect of temperature on the structure and angular jumps of water due to hydrophobicity using first principles molecular dynamics simulations. The average intermolecular distance between the central oxygen and four nearest neighbors is found to be the highest for water molecules in the solvation shell of TMA at 400 K, followed by the same at 330 K.

Effects of Doped N, B, P, and S Atoms on Graphene toward Oxygen Evolution Reactions.

Molecular oxygen and hydrogen can be obtained from the water-splitting process through the electrolysis technique. However, harnessing energy is very challenging in this way due to the involvement of the 4e reaction pathway, which is associated with a substantial amount of reaction barrier. After the report of the first N-doped graphene acting as an oxygen reduction reaction catalyst, the scientific community set out on exploring more reliable doping materials, better material engineering techniques, and developing computational models to explain the interfacial reactions.

Proton transfer from water to aromatic N-heterocyclic anions from DFT-MD simulations.

The phenomenon of proton transfer from water to six N-heterocyclic anions and free energy landscapes of this process are studied using both electronic structure calculations and first principles molecular metadynamics simulations. Our investigation involves microhydrated and aqueous phase interaction of water with six aromatic heterocyclic anions relevant to chemistry and biology: imidazolide, pyrrolide, benzimidazolide, 2-cyanopyrrolide, indolide, and indazolide. The basic structures of all these heterocyclic anions differ by substituted functional groups as well as fused rings.

Thermophysical Properties and Angular Jump Dynamics of Water: A Comparative DFT and DFT-Dispersion-Based Molecular Dynamics Study.

We present the first-principles molecular dynamics simulations of water molecules using two different levels of density functional theory within the Kohn-Sham scheme, namely, Becke-Lee-Yang-Parr (BLYP) and Perdew-Burke-Ernzerhof (PBE) with dispersion corrections such as D2 as well as D3 versions of Grimme dispersion correction and dispersion-corrected atom-centered potential. Our aim is to provide a comparative study of these functionals in explaining the thermophysical and structural properties along with nondiffusive jump dynamics of water molecules concerning the experimental data. The hydrogen bonding phenomenon is dependent on polarity, bonding, as well as nonbonding interactions, which requires thorough parametrization.

Dynamics and Spectral Response of Water Molecules around Tetramethylammonium Cation.

Till now, there has been ambiguity about the structural heterogeneity inside a solute solvation shell and the dynamical response of the surrounding solvent molecules. To address the dynamics and spectral response of solvent molecules, we performed first-principles molecular dynamics simulations for the comprehensive study of water's hydroxyl stretch frequency evolution due to environmental variations (also called "spectral diffusion") in the vicinity of a hydrophobe, tetramethylammonium (TMA) cation. The N-O radial distribution function (RDF), spatial distribution function (SDF), and combined distribution function (CDF) were calculated to provide information about the arrangement of water molecules around TMA.