2D polymers have emerged as one of the most promising classes of organic photocatalysts for solar fuel production due to their tunability, charge-transport properties, and robustness. They are however difficult to process and so there are limited studies into the formation of heterojunction materials incorporating these components. In this work, a novel templating approach is used to combine an imine-based donor polymer and an acceptor polymer formed through Knoevenagel condensation. Heterojunction formation is shown to be highly dependent on the topological match of the donor and acceptor polymers with the most active templated material found to be between three and nine times more active for photocatalysis than its constituent components. Transient absorption spectroscopy reveals that this improvement is due to faster charge separation and more efficient charge extraction in the templated heterojunction. The templated material shows a very high hydrogen evolution rate of >20 mmol h−1 m−2 with an ascorbic acid hole scavenger but also produces hydrogen in the presence of only water and a cobalt-based redox mediator. This suggests the improved charge-separation interface and reduced trapping accessed through this approach could be suitable for Z-scheme formation.
KAUST Repository Item: Exported on 2023-06-20
Acknowledged KAUST grant number(s): CRG10
Acknowledgements: The authors would like to acknowledge financial support from KAUST Office of Sponsored Research CRG10, by EU Horizon 2020 grant agreement n°952911, BOOSTER, grant agreement n°862474, RoLA-FLEX, and grant agreement n°101007084 CITYSOLAR, as well as EPSRC Projects EP/T026219/1 and EP/W017091/1. This project received funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement no. 886664 (S.G.-C.), and China Scholarhip Council-Imperial Scholarship (S.Y.). The authors acknowledge the David Cockayne Centre for Electron Microscopy at University of Oxford for access to equipment financially supported by the EPSRC (EP/K040375/1 “South of England Analytical Electron Microscope”) and the Henry Royce Institute for Advanced Materials (EP/R00661X/1, EP/S019367/1, EP/R010145/1).
This publication acknowledges KAUST support, but has no KAUST affiliated authors.