A cobalt-based polyoxometalate catalyst for efficient visible-light-driven H2 evolution from water splitting

A cobalt-based polyoxometalate, Na 7 H 10 [Co 6 (H 2 O) 2 (PW 9 O 34 ) 2 (PW 6 O 26 )]·30H 2 O, was synthesized by a simple aqueous solution method. It showed catalytic activity for the visible-light-driven H 2 evolution from water splitting with eosin Y as the photosensitizer and triethanolamine as the electron donor. The initial rate of the H 2 evolution was 141   μmol   h −   1 , which was higher than that of Co 2   + cations (55   μmol   h −   1 ). The efficient catalytic activity was attributed to that the [B-PW 9 O 34 ] 9   − units in the sample act as electron transmitters to accelerate charge transfer. Moreover, a possible mechanism was proposed to explain the H 2 evolution from water splitting in the present system.