Adsorption Mechanism and Optical Behaviors of Typical Volatile Organic Compounds on Pristine and Cu/Ni‐Modified C₃N Monolayer: A First‐Principles Study

Abstract

In this paper, the geometric and electronic structure of four gas molecules, including CH4, CH2O, CH3Cl and C6H6, on pristine and Cu/Ni‐modified C3N monolayer are investigated by using First principles. The calculations show that the Cu/Ni‐doping can effectively strengthen the gas adsorption ability of C3N. Upon gas‐C3N configuration, the adsorption energies are CH2O (0.11 eV) > C6H6 (0.09 eV) > CH3Cl (0.08 eV) > CH4 (0.05 eV). For Cu‐C3N configuration, the adsorption energies are C6H6 (3.26 eV) > CH3Cl (3.24 eV) > CH4 (3.22 eV) > CH2O (3.13 eV). For Ni‐C3N configuration, the adsorption energies are CH2O (1.48 eV) > C6H6 (0.66 eV) > CH3Cl (0.39 eV) > CH4 (0.11 eV). It is worth mentioning that the magnetic moment is reduced to 0 µB when CH2O are adsorbed on Cu/Ni‐C3N, and the maximum charge transfer is 0.71 e, 0.62 e, respectively. Moreover, its optical properties of adsorption of Volatile organic compounds (VOCs) gas molecules are studied. It can be found that the two main absorption peaks locate at 3.0 × 105 cm−1 nm and 2.8 × 105 cm−1 nm at the range of ultraviolet and visible light. The calculated results provide the theoretical reference for Cu‐C3N‐based VOCs sensors.

Tunable ohmic van der Waals-type contacts in monolayer C3N field-effect transistors

“…[18][19][20] Another promising method for opening the bandgap of graphene is to replace carbon with nitrogen atoms, which creates a strong covalent organic framework. [21][22][23][24][25][26][27] Recently, crystalline carbon nitride C 3 N, a new 2D hole-free graphene-like material with a honeycomb structure and identical distribution of carbon and nitrogen atoms, has been successfully synthesized on a massive scale. 20,[28][29][30][31] Experiments have shown that the on/off ratio of 2D C 3 N FET is 6.2 × 10 10 , and the electron and hole mobilities reach 992 and 6220 cm 2 V −1 s −1 , respectively.…”

First-principles insights into the C6N7 monolayer as a highly efficient sensor and scavenger for the detection of selective volatile organic compounds

“…25 In addition, the increasing of the N-to-C ration in carbon nitrides generates novel electronic features and chemical/physical properties such as the tunable nanopore size and band gap and adjustable conductivity, which are promising for key applications. In this context, the CN-based monolayers have been extensively used in gas sensing and exhibited high sensitivity and selectivity towards toxic gas and VOCs such as C 2 N, 34–37 C 3 N, 38–41 CN, 42–44 C 3 N 2 , 45 C 7 N 6 , 46,47 C 6 N 7 , 48 g-C 3 N 4 , 49,50 and BC 6 N 51,52 monolayers, which further motivates people's enthusiasm to exploit new C x N y structures with high-performance gas sensing. In particular for the sensing of VOCs, Agrawal et al 39 has confirmed that the C 3 N monolayer has relatively high sensing performance for acetone and isopropanol detection, while Ma et al 40 has predicted that the Cu-doped C 3 N monolayer has promising potential for optical VOCs sensors.…”

“…In this context, the CN-based monolayers have been extensively used in gas sensing and exhibited high sensitivity and selectivity towards toxic gas and VOCs such as C 2 N, 34–37 C 3 N, 38–41 CN, 42–44 C 3 N 2 , 45 C 7 N 6 , 46,47 C 6 N 7 , 48 g-C 3 N 4 , 49,50 and BC 6 N 51,52 monolayers, which further motivates people's enthusiasm to exploit new C x N y structures with high-performance gas sensing. In particular for the sensing of VOCs, Agrawal et al 39 has confirmed that the C 3 N monolayer has relatively high sensing performance for acetone and isopropanol detection, while Ma et al 40 has predicted that the Cu-doped C 3 N monolayer has promising potential for optical VOCs sensors. The g-C 3 N 4 monolayer and its composites with metal and metal oxide were demonstrated to have comparatively better gas sensing performance for detecting and decontaminating VOCs (ref.…”

“…48 In addition, the excellent structural characteristics of C 6 N 7 monolayers are analogous to the other C x N y monolayers [26][27][28][29][30][31][32][33] such as C 2 N, g-C 3 N 4 , C 3 N 2 , and C 7 N 6 monolayers, which have been demonstrated to be promising candidates for gas sensors to monitor toxic gases and VOCs. [34][35][36][37][38][39][40][41][42][43][44][45][46][47][48] However, to our best knowledge, the adsorption behaviors and gas-sensing properties of VOCs on the C 6 N 7 monolayer for sensor exploration are still unknown, which motivates us to investigate the sensing performance and mechanism of the C 6 N 7 -based VOCs sensors.…”