Adsorption of atoms and molecules on s-triazine sheet with embedded manganese atom: First-principles calculations

Abstract

The mechanical, structural, electronic and magnetic properties of s-triazine sheet (C 6 N 6 ) with embedded Mn atom (Mn-C 6 N 6 ) is investigated under the influence of external environment using density functional theory. Our results show that Mn-C 6 N 6 system is structurally and mechanically stable. The binding energy of Mn embedded in C 6 N 6 sheet can be modulated under the influence of symmetric deformation and perpendicular electric field respectively. The semiconducting property of pure C 6 N 6 sheet is maintained upon embedment of Mn atom in the porous site. It is also found that small increment in bi-axial tensile strain enhances the band gap (from 0.630 eV at zero strain to 0.802 eV at 5% strain) while the magnetic moment of the embedded Mn atom is preserved. The electronic and magnetic properties of the Mn-C 6 N 6 systems are maintained up to 10 V/nm in electric field strength. We also explore the geometries, electronic and magnetic properties of Mn-C 6 N 6 with adsorbed atoms and molecules. The Mn-C 6 N 6 with adsorbed O atom and O 2 molecule systems shows half-metallic character whereas the remaining systems preserve their semiconducting property. The total magnetic moment 1 arXiv:1703.06466v1 [cond-mat.mtrl-sci] per unit cell in most of the systems is found to reduce as compared to that of the Mn-C 6 N 6 sheet. The reduction in magnetic moment can be related to the strong interactions among the Mn atom and the surrounding atoms which lead to the formation of low-spin configurations. Overall, our results indicate that the Mn-C 6 N 6 systems with and without adsorbed atoms and molecules can serve as potential candidates for future spintronics and catalysis applications.2

Phononic Stability Analysis of Two-Dimensional Carbon Nitride Monolayers

“…C 6 N 8 structures, C-N bond lengths vary between 1.29-1.45 Å. All these calculated results are in good agreement with previous studies [13][14][15][16][21][22][23]. Cohesive energy calculation is a way to determine the stability of a structure by evaluating the cohesion strength between the constituent atoms in the cell.…”

“…Researchers have proposed several new types of carbon nitride membranes by theoretical calculations [9][10][11], and some of these membranes have already been synthesized [12]. But among them mostly interested ones are C 6 N 6 and C 6 N 8 monolayers [13][14][15][16][17][18]. The synthesization, detailed structural characterization and stability of bulk graphitic C 6 N 6 and C 3 N 4 structures have been reported by several researchers [19][20][21].…”

Unraveling the Activity and Mechanism of TM@g-C4N3 Electrocatalysts in the Oxygen Reduction Reaction

“…Recently, two-dimensional (2D) atomically dispersed transition metal (TM) anchored graphitic carbon nitride single-atom catalyst (SAC) materials, such as TM@g-C 2 N, , TM@g-C 3 N 4 , , and TM@g-C 6 N 6 , have shown great potential for the ORR. The remarkable catalytic performance exhibited by SACs can be attributed to tunable active sites and electronic structure. ,− For instance, the maintenance of isolated TM atoms and incorporated nitrogen atoms contribute to the enhancement of activity. − Nevertheless, the strong electronegativity of nitrogen atoms may result in a strong binding strength with intermediates, which is not favorable for the ORR. − In order to adjust the adsorption strength between active site and intermediates, various strategies have been employed, including adjusting coordination atoms ,, and utilizing different kinds of carbon supports. , For instance, g-C 3 N 4 has a variety of active sites with different coordination environments according to different TM loading sites, thus exhibiting excellent catalytic performance. , Similar to g-C 3 N 4 , the experimentally synthesized g-C 4 N 3 monolayer is also a promising graphitic carbon nitride material .…”

“…It is critical for reducing the amount of noble metals and exploring non-noble-metal-based catalysts with high efficiency and low cost for the ORR. 11−14 Recently, two-dimensional (2D) atomically dispersed transition metal (TM) anchored graphitic carbon nitride single-atom catalyst (SAC) materials, such as TM@g-C 2 N, 15,16 TM@g-C 3 N 4 , 17,18 and TM@g-C 6 N 6 , 19 have shown great potential for the ORR. The remarkable catalytic performance exhibited by SACs can be attributed to tunable active sites and electronic structure.…”