fig5

Figure 5. (A) H₂S adsorption configurations and energies on NiO_x(200) and Bi₂Te₃ (110)/NiO_x(200); (B) Charge density difference and Bader charges (Δq) for H₂S adsorption (pink/blue: charge accumulation/depletion); (C and D) DFT-calculated band structures of Bi₂Te₃ before (C) and after (D) H₂S-adsorption (Dirac points in red); (E) Proposed H₂S sensing mechanism for Bi₂Te₃@NiO_x. DFT: Density functional theory.