Transparent half metallic g-C4N3 nanotubes: potential multifunctional applications for spintronics and optical devices

Mn-Doped black phosphorene for ultrasensitive hydrogen sulfide detection: periodic DFT calculations

This paper addresses the comparative detection capabilities of pristine (BP) and Mn-doped (MP1) black phosphorene sensors toward the noxious H₂S molecule within a periodic density functional framework. The most stable configuration of the H₂S molecule on MP1 preferred the placement of an S-H bond on top of the Mn dopant, while the H-S-H plane was slightly tilted with respect to the surface. The formation of the Mn-modified phosphorene sensor was found to be highly favorable (-3.79 eV), which also enhanced the stabilization of the H₂S molecule (-0.85 eV at HSE06/TZVP). The electronic band structures revealed a direct-to-indirect transition and the observation of an n-type semiconductor through Mn doping. The results indicated that the pristine phosphorene could be converted into an ultrasensitive reusable H₂S nanosensor in terms of both electric conductance (3747) and work function (11 times more sensitive) through Mn doping. The new sensor was also highly selective, with a sensitivity ratio of at least 52.6 with respect to the air components. The recovery time of the Mn-doped material (2.7 s at ambient temperature) was more promising than that of BP from a practical point of view. More discussion of the material is presented with the electronic properties, frontier molecular orbitals, and density of states at rest and under operating conditions.

Two-dimensional graphitic carbon nitride (g-C4N3) for superior selectivity of multiple toxic gases (CO, NO2, and NH3)

Using first principles calculations, we investigated the possibility of selecting multiple toxic gases using one substrate material. Here, we explored the transport property of H₂, N₂, O₂, CO, CO₂, NO_2, and NH₃ gas molecules on two-dimensional graphitic carbon nitride (2D g-C₄N₃). The homonuclear molecule such as H₂, N₂, and O₂ has very weak adsorption energy (equal to or less than 0.1 eV) and also CO₂ has an adsorption energy of 0.23 eV. In the typical toxic gas molecule adsorption systems, we found an appreciable charge transfer. In CO and NH₃ adsorption systems, the charge transfer of 0.397 and 0.418 electrons from the molecule to the substrate was found, while the NO₂ molecule gained 0.124 electrons from the substrate. Due to this large amount of charge transfer, we obtained large adsorption energies of 4.57, 1.29, and 1.93 eV in CO, NO_2, and NH₃ systems. Moreover, through the I-V curve calculations, we found large difference in the current. The calculated current was 21, 13.11, and 16.16 μA for CO, NO_2, and NH₃ systems at the bias voltage of 0.5 V. Our results imply that the 2D g-C₄N₃ can be a superior substrate material for sensing of multiple toxic gases.

Atomically Thin B doped g-C3N4 Nanosheets: High-Temperature Ferromagnetism and calculated Half-Metallicity

Since the graphitic carbon nitride (g-C₄N₃), which can be seen as C-doped graphitic-C₃N₄ (g-C₃N₄), was reported to display ferromagnetic ground state and intrinsic half-metallicity (Du et al., PRL,108,197207,2012), it has attracted numerous research interest to tune the electronic structure and magnetic properties of g-C₃N₄ due to their potential applications in spintronic devices. In this paper, we reported the experimentally achieving of high temperature ferromagnetism in metal-free ultrathin g-C₃N₄ nanosheets by introducing of B atoms. Further, first-principles calculation results revealed that the current flow in such a system was fully spin-polarized and the magnetic moment was mainly attributed to the p orbital of N atoms in B doped g-C₃N₄ monolayer, giving the theoretic evidence of the ferromagnetism and half-metallicity. Our finding provided a new perspective for B doped g-C₃N₄ spintronic devices in future.

A multifunctional material of two-dimensional g-C4N3/graphene bilayer

Using first-principles calculations, we present a multifunctional material of g-C₄N₃/graphene bilayer with great potentials in the field of spintronics and photocatalysis.

Half-metallic and magnetic properties in nonmagnetic element embedded graphitic carbon nitride sheets

The B- and Al-doped triazine-based g-C₃N₄ monolayers exhibit long-range half-metallic ferromagnetic order, and are potential candidates for spintronics applications.