Surfactant-Driven Hydrogen Evolution in Organic Nanoparticles Prepared by Nanoprecipitation

In this work, donor:acceptor (D:A) semiconducting organic nanoparticles were synthesized by nanoprecipitation using two different anionic surfactants: sodium 2-(3-thienyl)ethyloxybutylsulfonate (TEBS) and sodium dodecyl sulfate (SDS). In contrast to previous studies employing miniemulsion as the synthetic methodology, the SDS-stabilized dispersions exhibited superior photocatalytic performance, showing a 2-fold increase in hydrogen production. This enhanced activity is attributed to a more favorable D:A blend morphology that promotes exciton dissociation in the case of P3HT:PC61BM. Indeed, Janus nanoparticles were obtained when SDS was used, leading to a hydrogen evolution rate (HER) of 0.52 mmol·g–1·h–1, whereas TEBS produced core–shell nanoparticles with a reduced rate of 0.35 mmol·g–1·h–1. A similar trend was observed with a higher-performing D:A system, PTQ10:Y6. Although transient absorption spectroscopy did not reveal significant differences in exciton dissociation and charge dynamics between the samples, a higher charge extraction efficiency to the medium led to higher platinum cocatalyst loading for the SDS-stabilized nanoparticles, achieving a HER of 11.5 mmol·g–1·h–1, while TEBS-stabilized nanoparticles reached 6.8 mmol·g–1·h–1.