Artículos de revistas
Bias-dependent local structure of water molecules at a metallic interface
Fecha
2018-01-07Registro en:
Chemical Science. Cambridge: Royal Soc Chemistry, v. 9, n. 1, p. 62-69, 2018.
2041-6520
10.1039/c7sc02208e
WOS:000418376400007
WOS000418376400007.pdf
Autor
Universidade Estadual Paulista (Unesp)
Universidade Federal do ABC (UFABC)
Ctr Fis Mat
Donostia Int Phys Ctr
SUNY Stony Brook
Institución
Resumen
Understanding the local structure of water at the interfaces of metallic electrodes is a key issue in aqueousbased electrochemistry. Nevertheless a realistic simulation of such a setup is challenging, particularly when the electrodes are maintained at different potentials. To correctly compute the effect of an external bias potential applied to truly semi-infinite surfaces, we combine Density Functional Theory (DFT) and NonEquilibrium Green's Function (NEGF) methods. This framework allows for the out-of-equilibrium calculation of forces and dynamics, and directly correlates to the chemical potential of the electrodes, which is introduced experimentally. In this work, we apply this methodology to study the electronic properties and atomic forces of a water molecule at the interface of a gold surface. We find that the water molecule tends to align its dipole moment with the electric field, and it is either repelled or attracted to the metal depending on the sign and magnitude of the applied bias, in an asymmetric fashion.