Enhancing the Photocatalytic Activity of BiVO₄ for Oxygen Evolution by Ce Doping: Ce³⁺ Ions as Hole Traps

To enhance the photocatalytic activity of monoclinic BiVO 4 for O 2 evolution from water, Ce-doped BiVO 4 was prepared using the one-pot facile solvothermal method and characterized via XRD, Raman, XPS, and electrochemical impedance spectroscopy (EIS). The XPS spectra confirm that Ce component is Ce 3+ ions instead of Ce 4+ ions. From the structural characterization and the calculations of formation energies it has been stated that the doping of Ce 3+ ions takes place at Bi 3+ sites without changing the host structure. The as-prepared Ce-doped BiVO 4 samples display significantly enhanced photocatalytic O 2 evolution activities from water compared to pristine BiVO 4 . Density of states calculations indicate that Ce 3+ ions act as hole traps, thereby delaying the recombination of photogenerated electrons and holes. The results demonstrate that the substitution of the remaining monoclinic crystal structure may offer an attractive alternative approach for the doping of BiVO 4 to enhance the evolution activity of photocatalytic O 2 .