Potential magnetic structure in EuInAsrevealed by magnetization and thermodynamic study.

We systematically investigate the magnetization and thermodynamic responses associated with the antiferromagnetic (AFM) transitions in magnetic semiconductor EuInAs. The linear thermal expansion measurements reveal thataxis expands whereasandaxes contract with the onset of the two AFM transitions atTN1andTN2. Using a simplified mean-field model incorporating AFM exchange interactions, easy-axis anisotropy, and Zeeman coupling, we analyze the potential magnetic structure change associated with the spin-flop and spin-flip transitions in field.

Tunable electronic and optical properties of ferroelectric WS/GaOheterostructures.

To integrate two-dimensional (2D) materials into van der Waals heterostructures (vdWHs) is regarded as an effective strategy to achieve multifunctional devices. The vdWHs with strong intrinsic ferroelectricity is promising for applications in the design of new electronic devices. The polarization reversal transitions of 2D ferroelectric GaOlayers provide a new approach to explore the electronic structure and optical properties of modulated WS/GaOvdWHs.

Reconfigurable band alignment of SWSe/h-BP heterostructures for photoelectric applications.

The integration of two-dimensional (2D) materials into van der Waals heterostructures (vdWHs) is regarded as an effective strategy for fabricating multifunctional devices. Herein, the effects of the vertical electric field and biaxial strain on the electronic, optical and transport properties of SeWS (SWSe)/h-BP vdWHs are systematically investigated using density functional theory calculations. The study shows that electric fields and biaxial strain can modulate not only the band gap but also the band alignment to produce multifunctional device applications.

BN cluster-doped graphdiyne as visible-light assisted metal-free catalysts for conversion CO to hydrocarbon fuels.

Carbon dioxide electrochemical reduction reaction (CORR) under ambient conditions provides an intriguing picture for conversion of CO to useful fuels and chemicals. Here by means of density functional theory (DFT) computations, the formation configuration and CORR catalytic activity of boron nitrogen cluster-doped graphdiyne (BN-doped GDY) were systematically investigated. The band structure and optical adsorption spectra reveal that BN-doped GDY exhibits semiconductor with the band gap of 0.

Smart Removal of Dye Pollutants via Dark Adsorption and Light Desorption at Recyclable BiOCO Nanosheets Interface.

The adsorbents for water treatment and purification are commonly not recyclable because of the lack of a reagent-less "switch" to readily release the adsorbed compounds. Herein, the interface of BiOCO (BOC) nanosheets is designed, synthesized, and modified with citric acid, namely, modified BiOCO (m-BOC). The m-BOC is able to selectively adsorb methylene blue (MB) in the dark and the adsorbed MB could be released in the light from m-BOC without the addition of any chemicals.

Graphdiyne coordinated transition metals as single-atom catalysts for nitrogen fixation.

The reduction of N molecules to NH is a very challenging task in chemistry. The electrocatalytic nitrogen reduction reaction (NRR) is a promising technology for NH synthesis. By using first-principles calculation, a new class of single-atom catalysts (SACs), graphdiyne coordinated single transition metal atoms (TM@GDY, TM = Sc-Zn, Y-Cd, and La-Hg) were designed, and the NRR catalytic character of TM@GDY was systematically investigated.

Steady semiconducting properties of monolayer PtSe with non-metal atom and transition metal atom doping.

Based on density functional theory, the electronic structure and magnetic properties of monolayer PtSe doped with different atoms were studied. The Pt and Se atoms are replaced by a transition metal atom (Mn) and a non-metal atom X (X = N, P, As), respectively. The pristine monolayer PtSe is a semiconductor with an indirect band gap of 1.

Charge-compensated co-doping of graphdiyne with boron and nitrogen to form metal-free electrocatalysts for the oxygen reduction reaction.

The development of metal-free catalysts for the oxygen reduction reaction (ORR) is critical for rechargeable metal-air batteries and full cells. Various light non-metallic-atom-doped graphdiyne (GDY) materials have been designed based on density functional theory and evaluated as efficient ORR electrocatalysts. Volcano curve correlations between the overpotential and Gibbs adsorption free energies of oxygenated intermediates have been derived for the ORR.

Molecule-level graphdiyne coordinated transition metals as a new class of bifunctional electrocatalysts for oxygen reduction and oxygen evolution reactions.

Single-atom catalysts (SACs) are highly desired for maximizing the efficiency of metal atoms and can entail high selectivity and activity. Bifunctional catalysts enable higher performance and lower cost than two single-function catalysts. Supported single-atom bifunctional catalysts are therefore of great economic interest and scientific importance.

Graphdiyne doped with sp-hybridized nitrogen atoms at acetylenic sites as potential metal-free electrocatalysts for oxygen reduction reaction.

Exploring metal-free electrocatalysts with high efficiency and lower cost for oxygen reduction reaction (ORR) is necessary to realize the commercialization of fuel cells. In this paper, the ORR mechanisms on nitrogen-doped graphdiyne (GDY) are investigated using the first principles calculations. It is found that the GDY doped with sp-hybridized N at acetylenic sites can activate molecular oxygen (O).

Effect of toxic ligands on O binding to heme and their toxicity mechanism.

Heme, as the cofactor and active site of Hb, enables Hb to carry out the necessary function required for O2 management for life, that is, reversible O2 binding for transport. In this paper, the microscopic mechanism of heme-associated poisoning has been elucidated from the perspective of electronic interaction by performing first-principles calculations. The results show that the functional groups (-CHO, -COOH, -NO2, -NH2) and CN exhibit a stronger affinity for heme than O2 and are more likely to occupy the O2 binding site, which results in the loss of the ability of heme to carry O2.

High-sensitivity fiber optic hydrogen sensor in air by optimizing a self-referenced demodulating method.

Self-referenced demodulating methods of fiber optic hydrogen sensors based on WO-PdPt-Pt composite film are studied in this paper. By employing the proper baseline intensity as sensing parameters, fluctuations of the sensing signal of the hydrogen sensor can be obviously depressed, and sensitivity can be greatly improved. Experimental results show that the resolution of the hydrogen sensor can reach 3 parts per million (ppm) when the hydrogen concentration is lower than 1000 ppm.

Ultrathin β-tellurium layers grown on highly oriented pyrolytic graphite by molecular-beam epitaxy.

Monolayer tellurium (Te) or tellurene has been suggested by a recent theory as a new two-dimensional (2D) system with great electronic and optoelectronic promises. Here we present an experimental study of epitaxial Te deposited on highly oriented pyrolytic graphite (HOPG) by molecular-beam epitaxy. Scanning tunneling microscopy of ultrathin layers of Te reveals rectangular surface cells with the cell size consistent with the theoretically predicted β-tellurene, whereas for thicker films, the cell size is more consistent with that of the [101[combining macron]0] surface of the bulk Te crystal.

Theoretical study on geometric, electronic and catalytic performances of Fe dopant pairs in graphene.

The formation geometries, electronic structures and catalytic properties of monovacancy and divacancy graphene sheets with two embedded Fe dopants (2Fe-MG and 2Fe-DG) have been systematically investigated using the first-principles calculations. It was found that the configuration of 2Fe-DG is slightly more stable than that of 2Fe-MG sheets and the two doped Fe atoms in graphene (2Fe-graphene) as active sites could regulate the stability of gas molecules. In addition, the adsorption of O and CO molecules could modulate the electronic and magnetic properties of 2Fe-graphene systems.

Band structure engineering in a MoS/PbI van der Waals heterostructure via an external electric field.

Band structure engineering in a MoS/PbI van der Waals (vdW) heterostructure under an external electric field (E) is investigated using density functional theory (DFT). It is demonstrated that the MoS/PbI vdW heterostructure has a type-II heterojunction with a direct bandgap, and thus the lowest energy electron-hole pairs are spatially separated. Meanwhile, the band structure could be effectively modulated under an E and the bandgap shows linear variations with the E, indicating a giant Stark effect.