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

•A cobalt-based polyoxometalate was synthesized by a simple aqueous solution method.•It showed efficient catalytic activity for the visible-light-driven H2 evolution.•[B-PW9O34]9 − units act as electron transmitters to accelerate charge transfer.•A possible mechanism of the visible-light-driven H2 evolution was proposed.

A cobalt-based polyoxometalate, Na7H10[Co6(H2O)2(PW9O34)2(PW6O26)]·30H2O, was synthesized by a simple aqueous solution method. It showed catalytic activity for the visible-light-driven H2 evolution from water splitting with eosin Y as the photosensitizer and triethanolamine as the electron donor. The initial rate of the H2 evolution was 141 μmol h− 1, which was higher than that of Co2 + cations (55 μmol h− 1). The efficient catalytic activity was attributed to that the [B-PW9O34]9 − units in the sample act as electron transmitters to accelerate charge transfer. Moreover, a possible mechanism was proposed to explain the H2 evolution from water splitting in the present system.

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