DFT study on the adsorption of 1H-benzotriazole on the (1 1 1) surface of modelled Cu–25%Zn brass

Abstract

The adsorption of 1H-benzotriazole (BTAH) on the (1 1 1) surface of modelled Cu–25%Zn brass is investigated using density functional theory calculations. In the one-atom modes, BTAH can uprightly adsorb on both copper and zinc sites via the N2 or N3 atoms of azole fragment and exhibit the σ-character interaction with the surface. The adsorption of BTAH in the two-atom modes is energetically more favorable than in the one-atom modes. However, the involvement of the zinc atom slightly decreases the adsorption strength of BTAH on the surface for both one-atom and two-atom modes. In the adsorption via the N2 atom, the dissociation barrier of BTAH on the copper atom is higher than on the zinc atom. By contrast, the exothermicity of dissociation reaction on the zinc atom is lower. The flat adsorption of BTAH exhibits a physisorption geometry on the surface of Cu–25%Zn without the strong interaction between the benzene fragment and the surface. With the dissociation, the N2 and N1 atoms move toward the zinc and copper atoms, respectively, and bond to them in the final state, resulting in the inclination geometry of the H-abstracted BTA with an angle of 25o between the molecular plane and the surface.