A new nickel substituted silicotungstate catalyst for efficient visible-light-induced hydrogen production from water splitting

A new nickel substituted silicotungstate ([Ni 4 (H 2 O) 2 (SiW 10 O 38 ) 2 ] 8− , Ni 2 SiW 10 ) was builded by NiCl 2 and Na 10 SiW 9 O 34 under mild conditions. It was used as a carbon-free homogeneous catalyst for the efficient visible-light-induced hydrogen production from water splitting with fluorescein sodium and triethanolamine as a photosensitizer and sacrificial electron donor, respectively. The initial rate of the H 2 evolution was 239 μmol h −1 , corresponding to a turnover frequency of 28 h −1 . Further results suggested that a reductive process was dominant in the present system for fluorescein sodium, and the production of H 2 came from water splitting.