Modification Effect of Organic Dyes on Photocatalytic Water Splitting Activity of KTa(Zr)O3

Effects of dye modification on photocatalytic water splitting were investigated using Zr-doped potassium tantalate (KTa(Zr)O-3). Various types of organic dyes, xanthenes, triphenylmethanes, carotenoids and polycyclic aromatic hydrocarbon, were investigated as modification dye. Among them. rhodamine 6G effectively improved the H-2 and O-2 formation rate of photocatalytic water splitting on KTa(Zr)O-3. It was found that the organic dye, which has a lowest unoccupied molecular orbital (LUMO) energy level at -0.9 V vs. NHE, shows a positive effect on the photocatalytic activity, suggesting that the suitable electron orbital level exists for charge transfer from KTaO3 to organic dye followed by Pt cocatalyst.