Hydrogen Bond Networks in the Electric Double Layer Dominate the Stability of Titanium Passivation Film

摘要

This study explores how hydrogen bo nding at electrochemical interfaces influences corrosion processes. While hydrogen bonds have recently been recognized for their role in electrocatalytic selectivity and hydrogen transfer, their impact on charge transfer at corrosion interfaces has not bee n thoroughly investigated. Our findings demonstrate that the hydrogen bonding network on metal surfaces significantly affects the corrosion process at atomic and electronic levels, highlighting how these bonds act as pathways for electron transfer. This insight offers a deeper understanding of the role of hydrogen bonding in corrosion electrochemistry. Building on this, our previous work provided detailed hydrogen bond characterization 1and introduced quantitative indicators for assessing hydrogen bonds 2.Additionally, we examine the effects of key sulfides—hydrogen sulfide (H 2S), carbonyl sulfide (COS), and dimethyl sulfide (DMS)—on the stability of titanium oxide passive films in seawater. Through density functional theory (DFT) and ab initio molecular dynam ics (AIMD), we analyze the adsorption and surface electronic properties of these sulfides on the anatase TiO2(101) surface. The optimal adsorption configurations for H2S, COS,and DMS on the anatase TiO2(101) surface are 2O b-vertical, O-down-vertical, and O b-parallel, with adsorption energies of -1.32, -0.67, and -1.86 eV, respectively. Through comparative AIMD simulationsof three different aqueous solutions on the TiO 2(101) surface, we have observed that COS exerts a more pronounced influence on the electrical double layer within 3.00 Å of the TiO2(101) surface. Specifically, the hydrogen atoms of water tend to aggregate towards the O b atoms, forming hydrogen bonds, which significantly impacts the corrosion resistance of the TiO2 surface.