Both PC and PEC investigations show

Both PC and PEC investigations show
that Ag deposition could enhance the % MB degradation than the
pure Cu2O electrode. Since the electron transfer rate for the MB oxidation
at WO3/BiVO4 electrode was not enhanced by Ag deposition,
the enhancement observed for Cu2O electrode would arise from the fact that the energy level of Ag is lower than that of the conduction
band of Cu2O [25]. Therefore, highly efficient electron separation
from conduction band of Cu2O via Ag resulted in a higher electron
transfer rate in this system.