In addition, the SEM image also shows the change of the surface
morphology of Cu2O when deposited with Ag nanoparticles
of the particle size in the range of 50–200 nm (Fig. 1C and D).
As shown in Fig. 1B and D, the modified Ag nanoparticles on a
WO3/BiVO4 substrate show higher density than that of the Cu2O
surface. Thus, it was confirmed that with the electrochemical technique
Ag nanoparticles could be deposited on both WO3/BiVO4 and
Cu2O surfaces.