We report here a theoretical study on 34 transition metal doped two-dimensional GaPS₄ catalysts denoted as transition metal transition metal@V_S-GaPS₄.

Using first-principle calculations, we investigate the mechanical, structural, and electronic properties and formation energy of 25 kinds of III–V binary monolayers in detail. A relative radius of the binary compound according to the atomic number in the periodic table is defined, and based on the definition, the 25 kinds of III–V binary compounds are exactly located at a symmetric position in a symmetric matrix. The mechanical properties and band gaps are found to be very dependent on relative radius, while the effective mass of holes and electrons are found to be less dependent. A linear function between Young’s modulus and formation energy is fitted with a linear relation in this paper. The change regularity of physical properties of B–V (V = P, As, Sb, Bi) and III–N ( III = Al , Ga, In, Tl) are found to be very different from those of other III–V binary compounds.

The structural and electronic properties of graphene/graphene-like Aluminum Nitrides monolayer (Gr/g-AlN) heterojunction with and without vacancies are systematically investigated by first-principles calculation. The results prove that Gr/g-AlN with nitrogen-vacancy (Gr/g-AlN-V_N) is energy favorable with the smallest sublayer distance and binding energy. Gr/g-AlN-V_N is nonmagnetic, like that in the pristine Gr/g-AlN structure, but it is different from the situation of g-AlN-V_N, where a magnetic moment of 1 μ_B is observed. The metallic graphene acts as an electron acceptor in the Gr/g-AlN-V_N and donor in Gr/g-AlN and Gr/g-AlN-V_Al contacts. Schottky barrier height ${\Phi }_{\mathrm{B},\mathrm{n}}$ by traditional (hybrid) functional of Gr/g-AlN, Gr/g-AlN-V_Al, and Gr/g-AlN-V_N are calculated as 2.35 (3.69), 2.77 (3.23), and 1.10 (0.98) eV, respectively, showing that vacancies can effectively modulate the Schottky barrier height. Additionally, the biaxial strain engineering is conducted to modulate the heterojunction contact properties. The pristine Gr/g-AlN, which is a p-type Schottky contact under strain-free condition, would transform to an n-type contact when 10% compressive strain is applied. Ohmic contact is formed under a larger tensile strain. Furthermore, 7.5% tensile strain would tune the Gr/g-AlN-V_N from n-type to p-type contact. These plentiful tunable natures would provide valuable guidance in fabricating nanoelectronics devices based on Gr/g-AlN heterojunctions.

The van der Waals heterostructures fabricated in two semiconductors are currently attracting considerable attention in various research fields. Our study uses density functional theory calculations within the Heyd-Scuseria-Ernzerhof hybrid functional to analyze the geometric structure and electronic structure of the g-C₃N₄/BiOBr(001) heterojunction in order to gain a better understanding of its photocatalytic properties. The calculated band alignments show that g-C₃N₄/BiOBr can function as a type-II heterojunction. In this heterojunction, the electrons and holes can effectively be separated at the interface. Moreover, we find that the electronic structure and band alignment of g-C₃N₄/BiOBr(001) can be tuned using external electric fields. It is also noteworthy that the optical absorption peak in the visible region is enhanced under the action of the electric field. The electric field may even improve the optical properties of the g-C₃N₄/BiOBr(001) heterostructure. Given the results of our calculations, it seems that g-C₃N₄/BiOBr(001) may be significantly superior to visible light photocatalysis.