Photo-catalytic H2 evolution over a series of Keggin-structure heteropoly blue sensitized Pt/TiO2 under visible light irradiation

We report the visible light-induced hydrogen generation over a series of Keggin-structure heteropoly blue (HPB) anions (PW12O403−, phosphotungstic blue (PTB), GeW12O404− (GTB), SiW12O404− (STB), BW12O405− (BTB)) sensitized Pt/TiO2 photo-catalysts. The sensitization of TiO2 by HPB was certified using photo-electrochemical measurements and UV-vis absorption spectra. PTB showed the most pronounced sensitization effect for TiO2 in those HPB anions and Pt/TiO2-PTB showed the highest hydrogen generation activity. The sensitization of TiO2 was significantly dependent on the reduction potential of HPA, which was determined by the kind of central atom in HPA.