Fig. 5
From: Water and seawater splitting with MgB2 plasmonic metal-based photocatalyst
Schematic of plasmon-enhanced water splitting on MgB2 nanostructures catalyst. (a) Schematic of Fermi-Dirac type distribution of high energy electrons originated from LSPs of small MgB2 nanostructures d < 300 nm, energy diagram of localisation of the Fermi level (EF) and LSPRs states for plasmonic MgB2 nanosheets and proposed mechanism of hot-electron induced dissociation of H2O on MgB2 surface (left part of panel). Overview of the energy level positions of surface electrons on the MgB2 nanosheets of large sizes d > 300 nm with respect to the redox potential of H+/H2 (0 V vs. SHE). The top potential of surface electrons (π-like B) is more negative than the redox potential of H+/H2 (0 V vs. SHE) while the bottom potential of surface electrons (σ-like B) is more positive than the redox potential of O2/H2O (1.23 V vs. SHE) (right part of panel). Electron-transfer processes locally redistributed electron densities across plasmon/semiconductor-like (indirect transfer (I)) and plasmon/absorbate (H2O or electrolyte molecules) interfaces (direct transfer (II)).
