Effect of the oxygen vacancy electronic state on Ni migration in Li(NiMnCo)O cathode material.

Cation migration coupled with oxygen vacancy formation is known to drive the layered to disordered spinel/rock-salt phase transformation in the high-Ni layered oxide cathodes of Li-ion batteries. However, the effect of different electronic states of oxygen vacancies on the cation migration still remains elusive. Here, we investigate Ni migration in delithiated Ni-rich LiNiMnCoO (hence LiNMC811) in the presence of neutral and charged oxygen vacancies by means of first-principles density functional theory (DFT) calculations coupled with the nudged elastic band (NEB) method.

Revealing the incorporation of an NH group into the edge of carbon dots for HO sensing the C-N⋯H hydrogen bond interaction.

We investigated hydrogen peroxide (HO) sensing on NH-functionalized carbon dots (Cdots) for three different -NH positions, and the N atom was found to be the active site using a quantum computational approach. B3LYP and 6-31G(d,p) were used for density functional theory (DFT) ground state calculations, whereas CAM-B3LYP and the same basis set were used in time-dependent density functional theory (TD-DFT) excited state calculations. Structural optimization showed that the HO is chemisorbed on 1-sim a C-N⋯H hydrogen bond interaction with an adsorption energy of -10.

Molecular insight into the role of zeolite lattice constraints on methane activation over the Cu-O-Cu active site.

Understanding the factors that influence the activity of a catalyst toward CH activation is of high importance for tuning the catalyst performance or designing new, better catalysts. Here, we performed a set of density functional theory (DFT) calculations on the H-CH bond cleavage over the Cu-O-Cu active site in the MOR zeolite with various Al-pair arrangements to obtain molecular insight into the structure-activity relation and clarify key parameters that define the Cu-O-Cu reactivity toward CH. We found that weakening of the Cu-O-Cu bond during CH activation is crucial for determining the O-H bond strength and thus the Cu-O-Cu reactivity.

DFT + U study of HO adsorption and dissociation on stoichiometric and nonstoichiometric CuO(1 1 1) surfaces.

Surface interaction through adsorption and dissociation between HO and metal oxides plays an important role in many industrial as well as fundamental processes. To gain further insights on the interaction, this study performs dispersion-corrected Hubbard-corrected density functional theory calculations in HO adsorption and dissociation on stoichiometric and nonstoichiometric CuO(1 1 1) surfaces. The nonstoichiometric surfaces consist of oxygen vacancy defect and oxygen-preadsorbed surfaces.

DFT and microkinetic investigation of methanol synthesis via CO hydrogenation on Ni(111)-based surfaces.

A DFT study of methanol production via CO2 hydrogenation reactions on clean Ni(111) and Ni(111)-M (M = Cu, Pd, Pt, or Rh) surfaces has been performed. The reaction network of this synthesis reaction has been determined using energy profiles. The competing reaction network between the formate-mediated route and the carboxyl-mediated route is also presented.

Holey Assembly of Two-Dimensional Iron-Doped Nickel-Cobalt Layered Double Hydroxide Nanosheets for Energy Conversion Application.

Layered double hydroxides (LDHs) containing first-row transition metals such as Fe, Co, and Ni have attracted significant interest for electrocatalysis owing to their abundance and excellent performance for the oxygen evolution reaction (OER) in alkaline media. Herein, the assembly of holey iron-doped nickel-cobalt layered double hydroxide (NiCo-LDH) nanosheets ('holey nanosheets') is demonstrated by employing uniform Ni-Co glycerate spheres as self-templates. Iron doping was found to increase the rate of hydrolysis of Ni-Co glycerate spheres and induce the formation of a holey interconnected sheet-like structure with small pores (1-10 nm) and a high specific surface area (279 m  g ).

Density functional study of methyl butanoate adsorption and its C-O bonds cleavage on MoS-based catalyst with various loads of Ni promoters.

Due to the increasing demands of new and renewable energy sources by utilising plant oils, uncovering the underlying physico-chemical phenomena at the atomic level responsible for the effective deoxygenation plays a vital role in improving the performance of well-known as well as in looking for the possible new catalysts. This study aims at investigating the adsorption and C-O bonds cleavage of methyl butanoate (MB) over MoS-based catalyst with various loads of Ni promoters by using first-principles density functional theory (DFT). This study employs surface model that never been used by previous researchers for their investigations of adsorption and bonds cleavage on Ni promoted MoS-based catalysts.

A combined spectroscopic and TDDFT study of natural dyes extracted from fruit peels of Citrus reticulata and Musa acuminata for dye-sensitized solar cells.

This study reports the novel spectroscopic investigations and enhanced the electron transfers of Citrus reticulata and Musa acuminata fruit peels as the photosensitizers for the dye-sensitized solar cells. The calculated TD-DFT-UB3LYP/6-31+G(d,p)-IEFPCM(UAKS), experiment spectra of ultra-violet-visible spectroscopy, and Fourier transform infrared spectroscopy studies indicate the main flavonoid (hesperidin and gallocatechin) structures of the dye extracts. The optimized flavonoid structures are calculated using Density functional theory (DFT) at 6-31+G(d,p) level.

First principles calculation on the adsorption of water on lithium-montmorillonite (Li-MMT).

The interaction of water molecules and lithium-montmorillonite (Li-MMT) is theoretically investigated using density functional theory (DFT) based first principles calculation. The mechanism of water adsorption at two different water concentrations on Li-MMT as well as their structural and electronic properties are investigated. It is found that the adsorption stability in Li-MMT is higher in higher water concentration.

Absorption of lithium in montmorillonite: a density functional theory (DFT) study.

The absorption of lithium in montmorillonite [LiSi8(Al3Mg)O20(OH)4] was investigated using Density Functional Theory (DFT). The final position of lithium after absorption was found to be in good agreement with an experimental observation where lithium atom migrated from the interlayer into the vacant octahedral site of montmorillonite. The lithium absorbed on montmorillonite was held together by a very strong attraction between ions and exhibited an insulating behavior as depicted from the density of states curve.