Fig. 4: The normalized electron numbers of the valence band for different solids in contact with water and solution.
From: Understanding contact electrification at liquid–solid interfaces from surface electronic structure
a ZnO, b SnO2, c MgO, d HfO2, e Ta2O5, and f BaTiO3. The normalized electron numbers near the Fermi level for different solids in contact with water and solution. g ZnO, h SnO2, i MgO, j HfO2, k Ta2O5, and l BaTiO3.
