Synergistic Contribution of Oligo(ethylene glycol) and Fluorine Substitution of Conjugated Polymer Photocatalysts toward Solar Driven Sacrificial Hydrogen Evolution

Abstract

To separately explore the importance of hydrophilicity and backbone planarity of polymer photocatalyst, a series of benzothiadiazole‐based donor–acceptor alternating copolymers incorporating alkoxy, linear oligo(ethylene glycol) (OEG) side chain, and backbone fluorine substituents is presented. The OEG side chains in the polymer backbone increase the surface energy of the polymer nanoparticles, thereby improving the interaction with water and facilitating electron transfer to water. Moreover, the OEG‐attached copolymers exhibit enhanced intermolecular packing compared to polymers with alkoxy side chains, which is possibly attributed to the self‐assembly properties of the side chains. Fluorine substituents on the polymer backbone produce highly ordered lamellar stacks with distinct π–π stacking features; subsequently, the long‐lived polarons toward hydrogen evolution are observed by transient absorption spectroscopy. In addition, a new nanoparticle synthesis strategy using a methanol/water mixed solvent is first adopted, thereby avoiding the screening effect of surfactants between the nanoparticles and water. Finally, hydrogen evolution rate of 26 000 µmol g−1 h−1 is obtained for the copolymer incorporated with both OEG side chains and fluorine substituents under visible‐light irradiation (λ > 420 nm). This study demonstrates how the glycol side chain strategy can be further optimized for polymer photocatalysts by controlling the backbone planarity.

Recent advances in photoelectrochemical hydrogen production using I–III–VI quantum dots

“…1–5 Solar energy has emerged as a promising solution to these issues, owing to its environmental sustainability, abundant availability, and cost-effectiveness. 6–13 Remarkably, the annual solar radiation reaching Earth exceeds the global annual energy consumption by over 7500 times. Within this context, photoelectrochemical (PEC) water splitting is emerging as an efficient, economical, and clean approach to harness solar energy for hydrogen production through water electrolysis.…”