Visible-light photocatalytic H2 evolution over a series of transition metal substituted Keggin-structure heteropoly blues

The visible light photocatalytic H-2 evolution activities of a series of transition-metal substituted Keggin-structure heteropoly blues K6SiW11O39M(H2O)center dot nH(2)O (M = Co, Ni, Cu and Zn) were systematically studied with Pt nanoparticles as co-catalyst. The H-2 evolution rates were 150, 98, 65 and 48 mu mol h(-1)g(-1) for SiW11Cu, SiW11Ni, SiW11Co and SiW11Zn, respectively, meaning that the order of photocatalytic activity of these heteropoly blues from transition-metal substituted polyoxometalates was: SiW11Cu > SiW11Ni > SiW11Co > SiW11Zn. The catalysts could be efficiently reused for at least 5 cycles.