An efficient electron donor containing a silicon heteroatom for organic photocatalysts with high hydrogen production activity.

We report here 4,4-bis(2-ethylhexyl)-4 H -silolo[3,2- b :4,5- b ']dithiophene (SiDT) as an electron donor to construct a donor-acceptor type conjugated polymer (PSiDT-BTDO) photocatalyst with a narrow band gap by employing dibenzo[ b , d ]thiophene- S , S -dioxide as an electron acceptor. The resulting polymer PSiDT-BTDO could realize a high hydrogen evolution rate of 72.20 mmol h -1 g -1 under ultraviolet-visible light with a Pt co-catalyst, due to the enhanced hydrophilicity as well as the decreased recombination rate of photo-induced holes/electrons and the dihedral angles of the polymer chains. The high photocatalytic activity of PSiDT-BTDO reveals the promising application of the SiDT donor in designing high-performance organic photocatalysts for hydrogen evolution.