Developments of the efficient water-splitting electrodes under the visible light irradiation

Our recent works on the photoelectrochemistry and fabrication of the water-splitting photocatalyst for solar energy conversion were reported. The S-dope midgap states were determined by monitoring the effect of the photocurrent on the addition of several reductants. The midgap states for the S-doped anatase TiO2 has higher redox potentials than those of the Br ・/Br− and possesses the additional multiple oxidation states of S cations. The laser ablation of the BiVO4 and BiZn2VO6 photocatalytic particulates in water reduced these sizes and it was found that the thin film electrode prepared by calcining the laser-ablated BiVO4 and BiZn2VO6 suspensions showed higher photocurrent efficiencies compared with the electrodes prepared without laser-ablation. The composite electrode FTO/SnO2/BiVO4 and FTO/WO3/BiVO4 were prepared by a solution method and the photocurrent efficiencies for these electrodes were found to be increased due to the mediator effect of SnO2 and WO3, which helps the electrons in the conduction band of BiVO4 to transfer to the FTO. The new photocatalytic particulates that are active for oxygen evolution under the visible light irradiation was searched and the BiCu2PO6 was found to be active with the addition of sacrifice under the visible light irradiations