high efficiency for visible-light driven hydrogen evolution

abstract A molecular Keggin polyoxometalate catalyst K 7 [Co III Co II (H 2 O)W 11 O 39 ](1) was successfullysynthesized and efficiently catalyzed the hydrogen evolution. To the best of our knowl-edge, the molecular Keggin polyoxometalate catalyst 1 is the first reported poly-oxometalate containing cobalt with efficient hydrogen production activity under the visiblelight irradiation. Under the optimal photocatalytic condition (photoirradiation atl 420 nm, Eosin-Y as the photosensitizer, triethanolamine as the electron donor and Ptproduced in situ photoreduction as co-catalyst), the turnover number (TON/based oncatalyst) reached as high as 100; the initial quantum yield and the initial turnover fre-quency (TOF) at the first 10 min were 29% and 0.025 s 1 , respectively. The hydrogen evo-lution average rate of 1 achieved 13,395 mmol h 1 g , as far as we are concerned, which is1the highest among all the polyoxometalates photocatalytic systems reported so far. Apossible mechanism of the hydrogen evolution reaction was proposed on the basis ofsteady-state fluorescence decay studies.Copyright