The corresponding adsorption energy is determined to be -211 meV. The CO molecule somewhat

favors both H and B sites, giving an identical absorption energy of -128 meV (see Figure 1g). For simplicity, the configuration at the H site is chosen as the representative for CO. All of the following results for these adsorbates are obtained based on their most favorable configurations if not specified. Table 1 Results for gas molecules on monolayer MoS 2 calculated by LDA functional Gas H site TMsite TSsite B site h E a ΔQ h E a ΔQ h E A-1210477 research buy a ΔQ h E a ΔQ H2 2.62 -70 0.004 2.61 -82 0.004 3.02 -49 0.008       O2 2.79 -106 0.034 2.71 -116 0.041 3.19 -64 0.020       H2O 2.59 -234 0.012 2.67 -222 0.016 3.13 -110 0.009       NH3 2.46 -250 -0.069 2.61 -222 -0.051 3.21 -100 -0.024       NO 2.68 -195 0.011 2.90 -185 0.011 2.88 -152 0.039 2.83 -211 0.022 NO2 2.65 -276 0.100       2.71 -249 0.119 2.62 -249 0.114 CO 2.95 -128 0.020 3.22 -124 0.006 3.28 -86 0.016 3.15 -128 0.013 Equilibrium height between the center of mass of the molecule and the top S-layer of the MoS2 sheet (h, in Å), adsorption energy (E a , in meV), and charge transfer from MoS2 to the molecule (ΔQ, VX-689 mouse in e). Negative ΔQ means charge transfer from the molecule to

MoS2. Figure 1 Adsorption configurations. Top and side views of the most favorable configurations for (a) H2, (b) O2, (c) H2O, (d) NH3, (e) NO, (f) NO2, and (g) CO on monolayer MoS2. The blue and yellow balls represent Mo and S atoms, whereas the cyanine, red, gray, and black balls represent H, O, N, and C atoms, respectively. Additionally, calculations of the gas adsorption are also Dynein performed using GGA functional. Different from LDA functional which overestimates the adsorption energy, GGA functional usually has a tendency to underestimate it. Upon the application of the two kinds of functionals, the upper and lower bounds for adsorption

energy and other structural properties can be obtained [8]. The calculated values of equilibrium height and adsorption energy for gas molecules on MoS2 are listed in Table 2. Herein, two GGA functionals, PW91 and PBE, are used for the purpose of comparison. Both PW91 and PBE give a smaller adsorption energy compared to the LDA, whereas they show the molecules binding at an equilibrium height larger than that for LDA. Table 2 Results for gas molecules on monolayer MoS 2 calculated by PW91 and PBE functionals Gas Site LDA GGA-PW91 AZD1390 supplier GGA-PBE h E a h E a h E a H2 TM 2.61 -82 3.21 -4 3.07 6 O2 TM 2.71 -116 3.32 -11 3.40 -4 H2O H 2.59 -234 3.17 -37 3.14 -21 NH3 H 2.46 -250 2.99 -44 2.91 -24 NO B 2.83 -211 3.47 -14 3.25 -33 NO2 H 2.65 -276 3.33 -43 3.30 -15 CO H 2.95 -128 3.61 -13 3.