MB degradation was significantly
influenced by pH of the solution. To study the PEC process,
neutral pH was found to be suitable. A plausible schematic diagram
by the function of PEC on employing WO3/BiVO4 as a photo-anode
and Cu2O/Ag as a photo-cathode under visible light irradiation was
proposed. Under visible light irradiation and bias potential, at a
photo-anode a significant amount of holes (h+) are generated to
oxidize MB to CO2. The electrons from the photo anode were drawn
by bias potential, while at the photo cathode the reduction would
take place efficiently by the electron transfer from Cu2O conduction
band to Ag particles. This leads to the high efficiency of the
degradation of MB.