Exploring the sensing ability of B‐ and Si‐doped WS₂ monolayer toward CO and NO gas

Abstract

Searching for new two-dimensional (2D) materials to capture toxic gas molecules has drawn great attention from scientific community. In this work, the adsorption of CO and NO molecules on B-and Si-doped WS 2 monolayer (B:WS 2 and Si:WS 2 ) has been explored using first-principles calculations. Pristine WS 2 monolayer is a non-magnetic semiconductor with an energy gap of 1.81 eV. It is magnetized upon doping with B atom to form a half-metallic material, meanwhile the paramagnetic nature is preserved upon Si doping. CO and NO molecules are weakly physisorbed on pristine WS 2 monolayer. Doping strategies enhance significantly the adsorption process decreasing drastically the adsorption energy. The adsorbed gas molecules alter considerably the fundamental properties of the doped systems. Specifically, the magnetic properties of B:WS 2 system are quenched by both CO and NO molecules to form paramagnetic metallic and semiconductor materials, respectively. CO adsorption increases the energy gap of Si:WS 2 system, meanwhile the adsorbed NO molecule induces significant magnetism, leading to the emergence of the half-metallicity. Results presented herein may recommend B-and Si-doped WS 2 monolayer as promising candidates to detect and capture CO and NO molecules. Moreover, doping strategy may be used to functionalize 2D transition metal dichalcogenides for toxic gas sensing.

Tailoring gas sensing properties of WS2 monolayer via Nb and Co embedding for highly sensitive and selective detection of HCN and H2S gases: a first principle study

“…Close binding energy values were reported in previous works for the Co and Nb embedded MoS 2 in S vacancy [36,37]. Furthermore, as exhibited in figure 1(c), the WS 2 is a direct band gap semiconductor with a band gap of 1.91 eV, which is consistent with that previously reported [24,[38][39][40]. Here, the Nb and Co embedding result in a significant decrease in band gap to, 1.23 eV and 1.15 eV for Nb and Co, respectively.…”

“…As a result, while the adsorption capacity of all three gases is enhanced, the system demonstrates remarkable selectivity towards C 2 H 2 [23]. Additionally, B and Si-WS 2 have been reported to be promising candidates for CO and NO gas sensing [24], respectively, while As-WS 2 has been reported to show strong selectivity and sensitivity toward NO 2 gas [25].…”

Characteristics and performance of layered two-dimensional materials under doping engineering

“…4(c), the electrocatalytic activity of monolayers doped with diatomic B is evaluated as promising electrocatalysts for the production of CH 4 . 108 Nonmetallic dopant atoms N, Si, and P enhance the orbital hybridization between H 2 and monolayer MoS 2 , increases the adsorption energy of H 2 and advances the charge transfer; this paves the way for further research on the application of hydrogen storage in MoS 2 . 109 Zhao et al systematically studied the electronic structure, formation energy and transition level of MoSe 2 monolayers doped with group-VA and -VIIA atoms.…”

“…The B and Si doping strategies make WS 2 monolayers become a potential material for detecting and harvesting toxic gases as CO and NO. 108 Moreover, in Fig. 4(c), the electrocatalytic activity of monolayers doped with diatomic B is evaluated as promising electrocatalysts for the production of CH 4 .…”

“…4(c), the electrocatalytic activity of monolayers doped with diatomic B is evaluated as promising electrocatalysts for the production of CH 4 . 108…”