Gas-sensing detection in the carbon phosphide monolayer: improving COx sensitivity through B doping.

A challenge in 2D materials engineering is to find a nanodevice that is capable of detecting and distinguishing gas molecules through an electrical signal. Herein, the B-doped carbon phosphide monolayer (B-doped γ-CP) was explored as a gas sensor through a combination of density functional theory (DFT) and the non-equilibrium Green's function (NEGF). Formation of the B-doped system is governed by an exothermic process, and the doping increases bands crossing at the Fermi level, contributing to an increment in the number of transmission channels compared with the undoped system. The interaction between the nanodevice and each gas molecule (CO, CO2, NO, and NH3) was explored. The electronic transmission is characteristically modulated by each target molecule, enabling each to be distinguished through the conductance change in the material. Our finds propose B-doped γ-CP as a promising candidate for use in highly sensitive and selective gas nanosensors.

A high density nanopore 3-triangulene kagome lattice.

Nanopore-containing two-dimensional materials have been explored for a wide range of applications including filtration, sensing, catalysis, energy storage and conversion. Triangulenes have recently been experimentally synthesized in a variety of sizes. In this regard, using these systems as building blocks, we theoretically examined 3-triangulene kagome crystals with inherent holes of ∼12 Å diameter and a greater density array of nanopores (≥1013 cm-2) compared to conventional 2D systems. The energetic, electronic, and transport properties of pristine and B/N-doped 3-triangulene kagome crystals were evaluated through a combination of density functional theory and non-equilibrium Green's function method. The simulated scanning tunneling microscopy images clearly capture electronic perturbation around the doped sites, which can be used to distinguish the pristine system from the doped systems. The viability of precisely controlling the band structure and transport properties by changing the type and concentration of doping atoms is demonstrated. The findings presented herein can potentially widen the applicability of these systems that combine unique electronic properties and intrinsically high-density pores, which can pave the way for the next generation of nanopore-based devices.