Markedly different adsorption behaviors of gas molecules on defective monolayer MoS₂: a first-principles study

Abstract

Sulfur vacancy (SV) is one of the most typical defects in two-dimensional monolayer MoS2, leading to reactive sites. We presented a systematic study of the adsorption behaviors of gas molecules, CO2, N2, H2O, CO, NH3, NO, O2, H2 and NO2, on monolayer MoS2 with single SV by first-principles calculations. It was found that CO2, N2 and H2O molecules physisorbed at the proximity of single SV. Our adsorption energy calculations and charge transfer analysis showed that the interactions between CO2, N2 and H2O molecules and defective MoS2 are stronger than the cases of CO2, N2 and H2O molecules adsorbed on pristine MoS2, respectively. The defective MoS2 based gas sensors may be more sensitive to CO2, N2 and H2O molecules than pristine MoS2 based ones. CO, NO, O2 and NH3 molecules were found to chemisorb at the S vacancy site and thus modify the electronic properties of defective monolayer MoS2. Magnetism was induced upon adsorption of NO molecules and the defective states induced by S vacancy can be completely removed upon adsorption of O2 molecules, which may provide some helpful information for designing new MoS2 based nanoelectronic devices in future. The H2 and NO2 molecules were found to dissociate at S vacancy. The dissociation of NO2 molecules resulted in O atoms located at the S vacancy site and NO molecules physisorbed on O-doped MoS2. The calculated results showed that NO2 molecules can help heal the S vacancy of the MoS2 monolayer.

Effects of noble metal doping on hydrogen sensing performances of monolayer MoS2

“…Meanwhile, scientists also found that monolayer MoS 2 has some adsorption capacity for toxic gas molecules [19][20][21]. When toxic gases adsorbed on monolayer MoS 2 , the electronic structure of the monolayer MoS 2 is changed, so the monolayer MoS 2 might be a candidate material for toxic gases sensing [22][23][24]. Based on the previous researches, the monolayer MoS 2 might also be a candidate material which can be used for hydrogen detection.…”

Interaction between H2O, N2, CO, NO, NO2 and N2O molecules and a defective WSe2 monolayer

“…4(b), which is similar to the case of NO adsorption on the defective MoS2 monolayer. [42,43] The electronic structures of the CO and NO doped WSe2 monolayer are discussed. show that the WSe2 are p-doped by substituting Se for the CO or NO molecule.…”

Chemisorption of metallic radionuclides on a monolayer MoS2nanosheet

“…18 Especially, scientists believe that MoS 2 is a potential sensor material for toxic gases, such as CO, NO, HS 2 , NH 3 , SO 2 and so on. Using the rst principles calculation method, the electronic and magnetic properties of MoS 2 have been investigated, 19 and the adsorption energy and charge transfer of different kinds of toxic gas molecules adsorbed on monolayer MoS 2 have been reported, [20][21][22] and the result shows that MoS 2 can monitor toxic gases in the atmosphere. Based on this research, we think that MoS 2 might be a candidate material for radionuclide removal from the environment.…”