Hydrogen evolution by polymer photocatalysts; a possible photocatalytic cycle

We propose, supported by ab initio calculations, a possible photocatalytic cycle for hydrogen evolution by a prototypical polymer photocatalyst, poly( p -phenylene), in the presence of a sacrificial electron donor. As part of that cycle, we also introduce a family of related sites on the polymer that in the absence of a noble metal co-catalyst can facilitate the evolution of molecular hydrogen when the polymer is illuminated. The bottlenecks for hydrogen evolution, electron transfer from the sacrificial electron donor and hydrogen-hydrogen bond formation, are discussed, as well as how they could potentially be improved by tuning the polymer properties and how they change in the presence of a noble metal co-catalyst. We propose, supported by ab initio calculations, a possible photocatalytic cycle for hydrogen evolution by a prototypical polymer photocatalyst, poly( p -phenylene), in the presence of a sacrificial electron donor.