Search

The development of high-performance direct-Z Scheme heterojunctions as photocatalysts is the focus of current research, and it is also an effective way to improve the performance of photocatalysts. Based on this, we use density functional theory (DFT) to predict two-dimensional (2D) XSe2/SiH (X = Zr, Sn) van der Waals (vdW) heterojunction as a potential direct Z-scheme heterojunction photocatalyst. The results indicate that both heterojunctions exhibit a typical Type-II band edge arrangement. Furthermore, the small band gap and built-in electric field of the heterojunctions facilitate electronic transitions between the valence band (VB) and conduction band (CB), thereby increasing the probability of interlayer electron–hole (e−-h+) recombination within the heterojunction. This process is beneficial for the formation of direct-Z Scheme heterojunctions. In addition, the XSe2/SiH (X = Zr, Sn) heterojunction exhibits remarkable photogenerated electron and hole driving forces, along with exceptional light-trapping capabilities. Therefore, XSe2/SiH (X = Zr, Sn) heterojunction is a potential new photocatalyst. [ABSTRACT FROM AUTHOR]

Semiconductor photocatalysts are hampered by carriers' recombination problems that hinder their practical application. The rational design of direct Z-scheme heterojunctions based on two-dimensional (2D) materials is one of the effective ways to solve this problem. Therefore, we predicted 2D CrS2/boron phosphide (BP) van der Waals heterojunction as a potential direct Z-scheme photocatalyst based on density functional theory. The CrS2/BP heterojunction has a small direct band gap, which is favorable for light absorption. In addition, the built-in electric field promotes the separation and transfer of the desired carriers. Photogenerated electrons and holes are localized in the conduction band of the BP component and the valence band of the CrS2 component, respectively. In addition, it was found that the heterojunction obtained a relatively small band gap and a wide optical absorption range at + 4% and + 5% strains. Therefore, the CrS2/BP heterojunction is a new photocatalyst satisfying the direct Z-scheme charge transfer mechanism, which has a certain application value. [ABSTRACT FROM AUTHOR]

In this paper, a water-vegetation model with the infiltration feedback effect is considered. Firstly, through the linear stability analysis, we get the parameter area where Turing instability can occur. Next, by maximum principle, a priori estimates for positive steady-state solutions are obtained and sufficient conditions for the nonexistence of nonconstant positive steady-state solution are given. Moreover, the steady-state bifurcations at both simple and double eigenvalues are analyzed separately. We establish the global structure of the bifurcation from simple eigenvalues and get the sufficient condition to determine the bifurcation direction. For the case of double eigenvalues, the techniques of space decomposition and the implicit function theorem are used. Finally, we verify and supplement the theoretical analysis results with numerical simulations. [ABSTRACT FROM AUTHOR]

The direct Z-scheme van der Waals (vdW) heterojunctions based on biomimetic artificial photosynthesis are a promising strategy for enhancing photocatalytic activity. Therefore, the search for superior direct Z-scheme photocatalysts is an urgent task. Herein, we predicted the WSeTe/Zr2CO2 heterostructure as a potential direct Z-scheme photocatalyst based on density functional theory (DFT). The bands of the WSeTe/Zr2CO2 heterojunction follow a typical Type-II arrangement, where the interlayer band gap is smaller than that of the individual molecular layers, and staggered alignment of the large band-edge creates conditions that allow for a direct Z-scheme. The position of the Fermi energy levels of the two monolayers determines the formation of the built-in electric field pointing from WSeTe to Zr2CO2, promoting the desired interlayer electron–hole (e−–h+) recombination and suppressing the undesired carrier recombination. Finally, in-plane biaxial strain can effectively modulate the optoelectronic properties of the catalyst, while compressive strain has a more pronounced effect on the overpotential driving force of the material. Therefore, the WSeTe/Zr2CO2 heterojunction is an effective new photocatalyst satisfying the direct Z-scheme charge transfer mechanism with its specific application. [ABSTRACT FROM AUTHOR]

In the field of photocatalytic water splitting, the direct Z-scheme heterostructure is regarded as a promising photocatalyst configuration. In this paper, we use density functional theory to predict the Ti2CO2/CrSSe heterostructure as a potential direct Z-scheme heterojunction photocatalyst and investigate its electronic, optical, and heterojunction interface properties. The results show that the Ti2CO2/CrSSe heterojunction has a strong electrostatic attraction between the electrons in the conduction band of Ti2CO2 and the holes in the valence band of CrSSe due to the small interlayer band gap, which can realize the rapid interlayer electron-hole (e−–h+) recombination. The redistribution of charge results in a built-in electric field that prevents unwanted electron and hole migration. In addition, the Ti2CO2/CrSSe van der Waals (vdW) heterojunction exhibits excellent light absorption, and its redox ability has been improved. These properties indicate that Ti2CO2/CrSSe heterostructure is a promising photocatalyst. [ABSTRACT FROM AUTHOR]

Direct Z-scheme based on biomimetic artificial photosynthesis is a promising strategy to enhance photocatalytic activity. The search for direct Z-scheme photocatalysts is imperative, and the photocatalytic efficiency is mainly influenced by the separation rate of photogenerated electron–hole (e--h+) pairs and the light capture ability. Herein, a two-dimensional (2D) van der Waals (vdW) heterostructure consisting of a monolayer of CrS2 and Sc2CF2 is predicted based on density functional theory (DFT) as a promising direct Z-scheme photocatalyst for water splitting. The CrS2/Sc2CF2 heterojunction possesses a large energy band interleaving arrangement and a small interlayer band gap, and the orientation of the built-in electric field promotes interlayer carrier complexes, with electrons and holes localized at the highest redox energy level, respectively. In addition, the CrS2/Sc2CF2 heterojunction possesses a high overpotential driving force and excellent light harvest ability. Our calculations indicate that the CrS2/Sc2CF2 heterojunction is a promising new photocatalyst. [ABSTRACT FROM AUTHOR]

The direct Z-scheme van der Waals (vdW) heterojunctions based on biomimetic artificial photosynthesis are a promising strategy for enhancing photocatalytic activity. Therefore, the search for superior direct Z-scheme photocatalysts is an urgent task. Herein, we predicted the WSeTe/Zr 2 CO 2 heterostructure as a potential direct Z-scheme photocatalyst based on density functional theory (DFT). The bands of the WSeTe/Zr 2 CO 2 heterojunction follow a typical Type-II arrangement, where the interlayer band gap is smaller than that of the individual molecular layers, and staggered alignment of the large band-edge creates conditions that allow for a direct Z-scheme. The position of the Fermi energy levels of the two monolayers determines the formation of the built-in electric field pointing from WSeTe to Zr 2 CO 2 , promoting the desired interlayer electron-hole (e - -h + ) recombination and suppressing the undesired carrier recombination. Finally, in-plane biaxial strain can effectively modulate the optoelectronic properties of the catalyst, while compressive strain has a more pronounced effect on the overpotential driving force of the material. Therefore, the WSeTe/Zr 2 CO 2 heterojunction is an effective new photocatalyst satisfying the direct Z-scheme charge transfer mechanism with its specific application.