Electric Field Effects on Electron Transfer between H+ and Carbon-Based Electrode Surfaces: A DFT and Anderson–Newns Hamiltonian Analysis Study

Abstract

Abstract To investigate the nature of the characteristic properties (especially the wide potential window and the low background current) of boron-doped diamond electrodes, we discuss electric field effects on the electron transfer process between the diamond surface and a proton based on density functional theory (DFT) and Anderson–Newns Hamiltonian analysis. All of the necessary data for this analysis were obtained by a “finite-field DFT method” at the level of B3LYP/6-31G and natural bond orbital analysis (NBO). The diamond and graphite electrode surfaces were modeled by corresponding clusters. We investigated the differences in the electric-field response of the density of states (DOS) peak of the proton 1s orbital and the number of electrons on the proton for the cases of a diamond cluster and a graphite cluster. These differences are attributable to the differences in the overlap between the proton 1s orbital and the surface orbitals. We discuss the relationship between this electric-field effect on the DOS peak, critical points of the Q-<n>curve and two characteristic properties of diamond electrodes, that is, low background currents and wide potential windows.