Uncovering the electrochemical interface of low-index copper surfaces in deep groundwater environments

• Using a combination of a sophisticated modeling protocol and well-established electrochemical techniques, we unravel the chemical composition of the low-index surfaces of copper in groundwater environments at different ion concentrations, pHs, and redox potentials. By carefully linking density functional theory (DFT) and cyclic voltammetry (CV), we are able to extract fundamental information on interfaces of broad significance. Herein, we focus on the case of groundwater found in deep geological environments of importance to the planned constructions of disposal repositories for spent nuclear fuel around the world. Within the error margins of DFT, we can assign adsorption structures and compositions to the current peaks of the CVs. It is found that among the groundwater ions of main interest (i.e. sulfide, bisulfide, sulfate, chloride and bicarbonate), sulfides (HS-, S2-) bind strongest to the surface, and are likely to dominate at the interfaces under the deep geological conditions relevant for repositories of spent nuclear fuel.

Subject headings

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

Keyword

Copper corrosion

DFT modeling

Cyclic voltammetry

Single-crystal surface

Ionic adsorption/desorption

Publication and Content Type

ref (subject category)

art (subject category)