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In this work, we systematically explore the effect of four-phonon (4ph) scattering on the lattice thermal conductivity (κ l) of γ -graphyne based on the atomic cluster expansion potential for carbon (C-ACE) combined with a phonon Boltzmann transport equation. The reliability of C-ACE in assessing the thermal transport properties of γ -graphyne is confirmed through comparing the results of phonon dispersion relation and κ 3 p h (only considering 3ph scattering) derived from C-ACE and density functional theory calculations. Regular residual analysis indicates that there might exist a strong 4ph interaction in γ -graphyne, and calculations further demonstrate κ 3 p h + 4 p h (considering 3ph scattering in an iterative solution and 4ph scattering in relaxation time approximation) is indeed reduced by 69.8% relative to κ 3 p h . From the analysis of scattering rates in γ -graphyne, one can intuitively observed that the 4ph scattering occupies a highly significant position in total phonon scattering, which greatly suppresses the κ l. The strong 4ph scattering in γ -graphyne is primarily due to the reflection symmetry selection rule less restricts 4ph scattering process for an out-of-plane flexural acoustic mode. The findings presented in this work demonstrate the reliability of C-ACE based accelerated calculations on the κ l of γ -graphyne, as well as reveal that the strong 4ph scattering in γ -graphyne significantly reduces its κ l , which will greatly promote the application of γ -graphyne and graphyne family in the field of thermoelectricity. [ABSTRACT FROM AUTHOR]

Constructing metal-semiconductor interfaces by loading metal atoms onto two-dimensional material to build atomically dispersed single-atom catalysts (SACs) has emerged as a new frontier for improving atom utilization and designing multifunctional electrocatalysts. Nowadays, studies on black phosphorus nanosheets in electrocatalysis have received much attention and the successful preparation of metal nanoparticle/black phosphorus (BP) hybrid electrocatalysts indicates BP nanosheets can serve as a potential support platform for SACs. Herein, by using large-scale ab initio calculations, we explored a large composition space of SACs with transition metal atoms supported on BP monolayer (M-BP) and built a comprehensive picture of activity trend, stability, and electronic origin towards oxygen reduction and evolution reaction (ORR and OER) and hydrogen evolution reaction (HER). The results show that the catalytic activity can be widely tuned by reasonable regulation of metal atoms. Ni-, Pd-, and Pt-BP could effectively balance the binding strength of the target intermediates, thus achieving efficient bifunctional activity for OER and ORR. Favorable bifunctional catalytic performance for OER and HER can be realized on Rh-BP. Especially, Pt-BP exhibits promising trifunctional activity towards OER, ORR, and HER. Multiple-level corrections among overpotential, Gibbs free energy, orbital population, and d-band center reveal that the trend and origin of catalytic activity are intrinsically determined by the d-band center of metal sites. The thermodynamic and dynamic stability simulations demonstrate that the active metal centers are firmly anchored on BP substrate with intact M-P bonds. These findings provide a theoretical basis for the rational design of BP-based SACs toward promising multifunctional activity. [ABSTRACT FROM AUTHOR]

In Janus photocatalysts, intrinsic dipole (P) plays an important role in the separation of photogenerated carriers and photocatalytic activity for water splitting. However, effectively switching the direction of the P vector between different surfaces is still an open issue. Based on first-principles calculation, we find that the P vector relies on charge distribution, while the distribution of the conduction band maximum-distributed reduction reaction surfaces (Sc) and valence band minimum-distributed oxidation surfaces (Sv) depends on the orbital hybridization in GaOI-based Janus. The direction of the P vector can be switched between Sc and Sv by substituting a metal or halogen atomic layer. The P vector in the direction from Sc to Sv releases bandgap limitation, broadens the light absorption range, and improves high carriers' mobility and solar-to-hydrogen efficiency (STH) efficiency, while the P vector pointing from Sv to Sc hinders the photocatalytic activity of GaOI-based Janus. Based on the investigation of STH efficiency and redox reactions, GaInOI is found to be a potential photocatalyst for overall water splitting. The stability of the Janus is studied by ab initio molecular dynamics and phonon diffusion spectrum. Current work proposes that switching the direction of the P vector between Sv and Sc is a potential route to regulate the band structure, optical absorption, and photocatalytic activity in GaOI-based Janus. [ABSTRACT FROM AUTHOR]

The experimentally synthesized graphene-type boron single layer (g-borophene) and its hydrogenated derivative (borophane in Cmmm symmetry) have been confirmed as normal metals, which are not appropriate for applications in the semiconductor field. Based on first-principles calculations, a new adsorption pattern (P6/mmm) with semiconducting feature has been proposed as a metastable phase for hydrogenated borophene. The results show that P6/mmm phase is both dynamically and mechanically stable. Its total energy is 4.829 eV atom−1, which is slightly higher than that of the ground state Cmmm configuration (4.858 eV atom−1). The HSE06-based band structures show that P6/mmm phase is a semiconductor with an indirect band gap of 1.86 eV and such a band gap can be effectively modulated by external strains. Our work shows that surface hydrogenation has the opportunity to induce a metal-insulator transition in two-dimensional borophene and provide a new two-dimensional semiconductor for potential applications in nano-electronic devices. [ABSTRACT FROM AUTHOR]

In monolayer transition metal dichalcogenides, defects, such as chalcogen vacancies, play an important role in determining their properties. Herein, monolayer MoSe2 with varying Se vacancy concentrations is successfully prepared by adjusting the amount of the precursors during the chemical vapor deposition synthesis. The Raman and low‐temperature photoluminescence spectra are systematically studied at varying defect concentrations. Furthermore, it is found that Se vacancies introduce in‐gap electronic states, leading to distinct localized exciton emissions, which can be engineered by controlling the concentration of Se vacancies. Density functional theory calculations indicate that the observed variations in localized exciton emission are attributed to the change of defect level with increasing defect concentration. The results provide insights into the influence of varying Se vacancy concentrations on defect‐induced Raman and PL spectroscopy in MoSe2. [ABSTRACT FROM AUTHOR]

The possibility of Fe loaded on BP (Fe@BP) as an efficient gas sensor for the detection of toxic gases such as NO2, NO, and CO is studied by the first‐principles calculation, and it is proposed that Fe@BP is an excellent gas‐sensitive material. The adsorption behaviors of gases on Fe@BP were analyzed in terms of adsorption configurations and electronic properties. It is found that all gases adsorbed on Fe@BP exhibit significantly enhanced interactions, and the adsorption intensity is much larger than that of molecules adsorbed on the surface of pure BP. Fe@BP has high selectivity for toxic and ambient gas molecules. In addition, the adsorption strength of NO2 and NO molecules on Fe@BP increases after compression strain is applied (within −3%), while the adsorption strength of CO decreases gradually. After the tensile strain is applied, the adsorption intensity of NO2 and NO is decreased, but that of CO is increased gradually. It is speculated that the strain causes changes in the electronic structure, which affects the adsorption behavior. The adsorption of NO has a stronger strain sensitivity. For these reasons, Fe@BP with high adsorption strength and strain selection is the ideal gas‐sensitive material. [ABSTRACT FROM AUTHOR]

This study used the DNA of Bacillus amyloliquefaciens Ba168 as a template to amplify the flagellin BP8-2 gene and ligate it into the fusion expression vector pCAMBIA1300-35S-EGFP after digestion for the construction of the expression vector pCAMBIA1300-EGFP-BP8-2. Next, using Nicotiana benthamiana as receptor material, transient expression was carried out under the mediation of Agrobacterium tumefaciens C58C1. Finally, the transient expression and subcellular localisation of flagellin BP8-2 protein were analysed using the imaging of co-transformed GFP under laser confocal microscopy. The results showed that flagellin BP8-2 was localised in the cell membrane and nucleus, and the RT-PCR results showed that the BP8-2 gene could be stably expressed in tobacco leaf cells. Furthermore, there was stronger antiviral activity against tobacco mosaic virus (TMV) infection in Nicotiana glutinosa than in BP8-2 and ningnanmycin, with an inhibitory effect of 75.91%, protective effect of 77.45%, and curative effect of 68.15%. TMV movement and coat protein expression were suppressed, and there was a high expression of PR-1a, PAL, and NPR1 in BP8-2-treated tobacco leaf. These results suggest that flagellin BP8-2 inhibits TMV by inducing resistance. Moreover, BP8-2 has low toxicity and is easily biodegradable and eco-friendly. These results further enrich our understanding of the antiviral mechanisms of proteins and provide alternatives for controlling viral diseases in agriculture. [ABSTRACT FROM AUTHOR]

Generating fully spin‐polarized currents (FSPC) and pure spin currents (PSC) are of great importance for spintronics. Half‐metallic ferromagnets, which generate 100% spin polarization, are considered as one of the most promising materials for applications in spintronics. However, the knowledge of intrinsic half‐metallic materials in the spin‐dependent photogalvanic effect is still poorly understood. Using first‐principle transport calculations, a robust approach is introduced to obtain FSPC and PSC by spin‐dependent photogalvanic effect in intrinsic half‐metallic materials. Based on the recently synthesized monolayer half‐metallic C(CN)3, a 2D spin photogalvanic device is built and it is demonstrated that the FSPC can be achieved in a wider photon energy range under both linearly and elliptically polarized light due to the half‐metallicity. It is intriguing to note that the device can be easily manipulated to transition between two modes: one for generating FSPC and another for generating PSC by setting the two leads in anti‐parallel configurations. Furthermore, a significant spin‐valve effect can be attained across various photon energies for both linearly and elliptically polarized light. The research shows that half‐metallic materials are an ideal platform for studying and generating FSPC and PSC, which presents a remarkable avenue for the development of advanced spintronic devices in the next generation. [ABSTRACT FROM AUTHOR]

Monolayer and few-layer CoPS3 have been successfully synthesized via an Au-assisted exfoliation technique, with their transport properties subsequently investigated by conductive atomic force microscopy. Rectification effects can be observed in CoPS3 nanosheets due to the Schottky junction formation at the Au/CoPS3 interface, especially in configurations comprising two or more layer flakes. The distinct transport properties between monolayer and few-layer samples demonstrate that the charge transport behavior in the vertical direction is associated with the van der Waals gap. The calculated electron affinity for CoPS3 is about 4.84 eV, as revealed by the thermionic emission model. The results obtained contribute to the knowledge base concerning the transport characteristics of ultrathin MPX3, facilitating further exploration of the transport behavior of these materials and their potential applications in novel electronic devices. [ABSTRACT FROM AUTHOR]