Insights into Photogenerated Carrier Dynamics and Overall Water Splitting of the CrS/GeSe Heterostructure.

Based on the nonadiabatic molecular dynamics (NAMD) simulations and the first-principles calculations, we explore the overall water-splitting schemes and the photogenerated carrier dynamics for two configurations (CG and CG) of the CrS/GeSe van der Waals heterostructures. The photocatalytic direct Z-schemes and carrier migration pathways for hydrogen and oxygen evolution reactions (HER/OER) are constructed based on the electronic properties. The solar-to-hydrogen efficiency (η' values) of the schemes can reach 10.

Electron-phonon coupling, bipolar effects, and thermoelectric performance of the CuSbS monolayer.

The thermoelectric performance of the CuSbS monolayer is determined using the relaxation times obtained from electron-phonon coupling calculations and the transport properties of phonons and electrons. Based on the fully relaxed structure, the lattice thermal conductivity and the electronic transport coefficients are evaluated by solving the Boltzmann transport equation for phonons and electrons under relaxation time approximation, respectively. The tendencies of the transport coefficients depending on the carrier concentrations and temperatures are studied to understand the thermoelectric performance.

Efficient photocatalytic hydrogen evolution and CO reduction by HfSe/GaAs and ZrSe/GaAs heterostructures with direct Z-schemes.

The elaborate configuration of the heterostructure is crucial and challenging to achieve high solar-to-hydrogen efficiency or CO reduction efficiency . Here, we predict two heterostructures composed of HfSe, ZrSe, and GaAs monolayers. The maximum of 42.

Opposite Sensing Response of Heterojunction Gas Sensors Based on SnO-CrO Nanocomposites to H against CO and Its Selectivity Mechanism.

Metal oxide semiconductor (MOS) gas sensors show poor selectivity when exposed to mixed gases. This is a challenge in gas sensors and limits their wide applications. There is no efficient way to detect a specific gas when two homogeneous gases are concurrently exposed to sensing materials.

2D XBiSe(X = Ga, In, Tl) monolayers with high carrier mobility and enhanced visible-light absorption.

The geometrical configurations of the XBiSe (X = Ga, In, Tl) monolayers are identified by employing the first-principles density functional theory calculations, and the stabilities are confirmed by phonon dispersion, formation energy, and ab initio molecular dynamics simulation, respectively. The bandgap and band edges, the density of states, the optical absorption, mobility, and effect of strain engineering are evaluated to understand the photoelectronic properties of the monolayers. The results show that the XBiSe monolayers have the indirect bandgaps of 1.

Preparation and fluorescence characterization of monodisperse core-shell structure SiO @SiO :Tb(1,2-BDC) phen microspheres by a sol-seed method.

The SiO @SiO :Tb(1,2-BDC) phen microspheres with monodispersed core-shell structure, are kind of fluorescent particles, which are prepared by a seeded growth method under the catalysis of glacial acetic acid (1,2-BDC, 1,2-benzenedicarboxylic acid; phen, 1,10-phenanthroline). Firstly, silica seed was fabricated by the hydrolysis of ethyl orthosilicate, and the Tb(1,2-BDC) phen was prepared by using 1,2-BDC and phen. Then, a thin mesoporous silica shell doped with Tb(1,2-BDC) phen was grown on the prepared monodisperse silica colloids.

Two-dimensional SiMI(M = Ge, Sn) monolayers as visible-light-driven photocatalyst of hydrogen production.

Two-dimensional (2D) materials of SiMI(M = Ge, Sn) monolayers are identified as promising visible-light-driven photocatalyst for hydrogen evolution reaction by DFT calculations. The dynamical and thermal stabilities of the two monolayers are confirmed by the phonon dispersion calculations and ab initiomolecular dynamics (AIMD) simulations, respectively.The results show that the two 2D materials have indirect bandgaps of 2.

The high power conversion efficiency of a two-dimensional GeSe/AsP van der Waals heterostructure for solar energy cells.

Constructing a van der Waals heterostructure is a practical way to promote the conversion efficiency of solar energy. Here, we demonstrate the efficient performance of a GeSe/AsP heterostructure in solar energy cells based on the first-principles calculations. The electronic properties, optical absorption, and optoelectronic properties are calculated to evaluate the efficiency of the newly designed heterostructure.

Direct laser cooling schemes for the triatomic SOH and SeOH molecules based on electronic properties.

Direct laser cooling is a very promising method to obtain cold molecules for various applications. However, a molecule with satisfactory electronic and optical properties for the optical scheme is difficult to identify. By suggesting criteria for the qualified molecules, we develop a method to identify the suitable polyatomic molecules for direct laser cooling.

Direct laser cooling the NH molecule with the pseudo-closed loop triplet-triplet transition including intervening electronic states.

Direct laser cooling molecule is useful way to obtain the accurate molecular spectroscopy. However, most of the reported direct laser cooling schemes are only involved the molecules with a singlet or doublet ground state because the one with a triplet ground state is more complex, especially when the first-excited state is not suitable for the pseudo-closed loop transition. Using NH as the prototype of the simplest heteronuclear molecule with a triplet ground state, we focus on constructing the direct laser cooling scheme with a pseudo-closed loop triplet-triplet transition including intervening electronic states.

First-principles investigation on the thermoelectric performance of half-Heusler compound CuLiX(X = Se, Te).

The remarkable thermoelectric performance is predicted for half-Heusler (HH) compounds of CuLiX (X = Se, Te) based on the first-principles calculation, the deformation potential (DP) theory, and semi-classical Boltzmann theory. The Slack model is employed to evaluate the lattice thermal conductivity and the result is in good agreement with the previously reported data. The results of mechanical properties demonstrate that CuLiSe is ductile but CuLiTe is brittle.

Photocatalytic water splitting for hydrogen generation driven by tetragonal, trigonal, hexagonal and cubic LiCoO and visible light.

The photocatalytic properties of LiCoO are not explored up to date although its cubic and trigonal structures are explored experimentally. Here, we investigate the feasibility of photocatalytic hydrogen production from water splitting driven by the tetragonal, trigonal, hexagonal and cubic LiCoO with the irradiation of the visible light. The band structure, density of state, optical absorption and mobility are calculated by the first-principles density functional theory.

High thermoelectric figure of merit and thermopower of HfTeat room temperature.

We predict a high thermoelectric efficiency of HfTe, based on the first-principles calculations of the electronic structure and thermal conductivity, and the transport coefficients obtained by using the semi-classical Boltzmann transport theory in a wide temperature and carrier concentration range. The lattice thermal conductivity is calculated based on the Slack model and the result is in good agreement with the experimental value. The results of all the thermoelectric transport coefficients demonstrate anisotropic characteristics with the obvious small values along with thedirection.

Formation of stable aggregates by fluid-assembled solid bridges.

When a colloidal suspension is dried, capillary pressure may overwhelm repulsive electrostatic forces, assembling aggregates that are out of thermal equilibrium. This poorly understood process confers cohesive strength to many geological and industrial materials. Here we observe evaporation-driven aggregation of natural and synthesized particulates, probe their stability under rewetting, and measure bonding strength using an atomic force microscope.

ZnCdO monolayer - A complex 2D structure of ZnO and CdO monolayers for photocatalytic water splitting driven by visible-light.

ZnO monolayer possesses band structure matching the conditions of water splitting for hydrogen generation but cannot well response to the visible light, while CdO one, contrariwise, have obvious optical absorption in the visible light range but no satisfactory band edges for the water splitting to produce hydrogen. Here, we predict a two-dimensional ZnCdO structure comprising of ZnO and CdO ones to achieve their strengths. The band structures, optical properties, carrier mobility, and the strain engineering for ZnCdO, ZnO and CdO monolayers are investigated by using the first-principles hybridization functional calculations.

Remarkably High Thermoelectric Efficiencies of the Half-Heusler Compounds BXGa (X = Be, Mg, and Ca).

The thermoelectric materials with high values of the dimensionless figure of merit () are among the most important new energy resources. Too much attention has been paid to the search of high- thermoelectric materials, and the one with = 5 has been reported recently. Here, a remarkably high = 7.

The spectroscopic properties of the low-lying excited states and laser cooling scheme of SrBr molecule.

The potential energy curves and the transition dipole moments for seven electronic states of SrBr molecule are obtained via the multi-reference configuration interaction method and the all-electron basis sets. The Davidson and relativistic corrections are also included. Based on the obtained potential energy curves, the rotational and vibrational energy levels of each electronic state are determined by solving the nuclear motion equation of the molecule.

2D AlP with high carrier mobility and tunable band structure.

The exploration of new monolayer materials always attracts much attention due to the extraordinary properties and promising applications. Here we predict two monolayered aluminum triphosphides (AlP) with C2/m and P3m1 space groups with a tunable bandgap under strain as the new members of the 2D XP family by using the first principles calculations. The stabilities of the predicted structures are confirmed with the phonon dispersion curves and molecular dynamics.

Theoretical insight on hybrid nanocomposites of graphene quantum dot and carbazole-carbazole dyes as an efficient sensitizer of DSSC.

The feasibility of the hybrid nanocomposites of the graphene quantum dot (GQD) and carbazole-carbazole dyes as the efficient sensitizer of dye-sensitized solar cells (DSSC) is investigated. By using the first principles density functional theory (DFT), we fully optimize the geometrical structures of GQD, the carbazole-carbazole dyes, and their hybrid nanocomposites. The harmonic frequency analysis is used to confirm the energy stability of the optimized structures.

Theoretical study on the low-lying excited electronic states and laser cooling feasibility of CuH molecule.

To evaluate the feasibility of the laser cooling of CuH molecule, we investigate the electronic properties, the vibrational and rotational characteristics of the molecule based on the multi-reference configuration interaction method with all-electron basis sets. The potential energy curves (PECs) of XΣ, AΣ, BΣ, aΣ, bΣ, eΣ, CП, DП, cП and dП states and the transition dipole moments between these states are calculated. The Schrödinger equation of nuclear movement is solved for each electronic state to obtain the rotational and vibration energy levels.

Photocatalytic hydrogen production from water splitting with N-doped β-GaO and visible light.

Based on the first principles calculations, the feasibility of the photocatalytic hydrogen production from water splitting driven by N-doped β-GaO in the visible light is investigated. The formation energy and dynamics properties are used to examine the stability of the doped structures. The absolute positions of the band energy edges are obtained and compared to the redox potentials of the hydrogen production reaction.

Chalcogens doped BaTiO for visible light photocatalytic hydrogen production from water splitting.

The pristine BaTiO has been experimentally confirmed to catalyze hydrogen production from water splitting, but the reaction cannot be driven by the visible light because of the wide energy band gap of BaTiO. To understand the feasibility of the reaction driven by the visible light of the strongest part of the solar energy, we have investigated the effect of different concentrations of oxygen group element dopants on the electronic and optical properties of BaTiO by using first-principles density functional theory calculations with meta-GGA + MBJ potential. The formation energy of each doped structure is calculated to examine the feasibility of synthesis in energy.

Group-IVA element-doped SrInO as potential materials for hydrogen production from water splitting with solar energy.

Band gap engineering can efficiently improve the photocatalytic activity of semiconductors for hydrogen generation from water splitting. Herein, we present a comprehensive investigation on the geometrical structures, electronic, optical, and potential photocatalytic properties and charge carrier mobility of pristine and group-IVA element-doped SrInO using first-principles density functional theory with the meta-GGA+MBJ potential. The calculated formation energies are moderate, indicating that the synthesis of the doped structures is experimentally feasible.

Theoretical studies on the feasibility of the hybrid nanocomposites of graphene quantum dot and phenoxazine-based dyes as an efficient sensitizer for dye-sensitized solar cells.

The feasibility of the hybrid nanocomposites of the graphene quantum dot (GQD) and the phenoxazine-based dyes as the efficient sensitizer of the dye-sensitized solar cell (DSSC) is investigated. Based on the first principles density functional theory (DFT), the geometrical structures of the separate GQDs, the phenoxazine-based dyes, and their hybridized nanocomposites are fully optimized. The energy stabilities of the obtained structures are confirmed by harmonic frequency analysis.