In present work we analyzed some electronic properties involved during the adsorption of BH4- on Cu(100), Ag(100) and Au(100) surfaces. Reactivity descriptors such as ionization energy, hardness, electrophilicity, frontier molecular orbitals, condensed Fukui function, adsorption energies and density of states were calculated to identify changes in the reactivity on Cu(100), Ag(100) and Au(100). The results suggest the BH4- adsorption is favored on Cu(100) more than on Ag(100) or Au(100). The BH4- -Au(100) system showed higher values of μ and ω in comparison with BH--Ag(100) and BH4- Cu(100) systems. Last results suggest that gold is a better electron acceptor in comparison with silver and copper. Also, the fraction of electrons transferred during the BH4- adsorption was calculated indicating a bigger electron transfer from BH4- to Cu(100) compared to Au and Ag.

En el presente trabajo analizamos algunas propiedades electrónicas involucradas durante la adsorción del BH4- sobre las superficies Cu(100), Ag(100) y Au(100). Se calcularon descriptores de reactividad tales como energía de ionización, dureza, electrofilicidad, orbitales moleculares frontera, función Fukui condensada, energías de adsorción y densidad de estados, para identificar cambios en la reactividad de las superficies Cu(100), Ag(100) y Au(100). Los resultados sugieren que la adsorción del BH- es favorecida sobre Cu(100) más que sobre Ag(100) y Au(100). El sistema BH4- -Au(100) mostró los valores mayores de μ y ω en comparación con los sistemas BH4- -Ag(100) y BH4- -Cu(100). Estos resultados sugieren que el oro es un mejor aceptor de electrones que plata o cobre. También se calculó la fracción de electrones durante el proceso de adsorción, los resultados indicaron que existe una mayor transferencia de carga del BH- hacia el cobre comparada con las obtenidas en Au y Ag.

In present work, we analyzed the copper electrodeposition onto GCE (System I) and HOPGE (System II) from perchlorate solutions. The current density transients obtained from system I and II were well described through a kinetic mechanism that involves four different contributions: (a) a Langmuir type adsorption process, b) an electron transfer from Cu2+→Cu+, (c) a 3D nucleation limited by a mass transfer reaction and (d) a proton reduction process. It was observed that the values of the nucleation rate, the number of active nucleation sites were increased with the overpotential and they are bigger onto GCE in comparison with HOPGE.