In Situ Self-Inflating-Modeled Giant-Vesicle-Like Quantum Dot Assembly for Biomimetic Artificial Photosynthesis

The study of biomimetic self-assembly is crucial for scientists aiming to understand the origin of life and construct biomimetic functional structures. In our endeavor to create a biomimetic photosynthetic assembly, we discover a self-inflation behavior that drives the components, MPA-CdSe quantum dots (QDs) and a solid cationic polyelectrolyte, CPPA, to form a giant-vesicle-like (GVL) architecture, termed GVL-QDs@CPPA. The in situ generation of osmotic pressure during the self-assembly of QDs onto swollen CPPA in water was found to cause this self-inflation process. The resulting vesicle-like structure exhibits spatial characteristics similar to those of natural photosynthetic cells, with QDs acting as pigments uniformly distributed on the CPPA membranes, which have embedded cobalt catalytic centers. This architecture ensures optimal absorption of visible light and facilitates efficient electron transfer between the QDs and catalytic centers. As a result, GVL-QDs@CPPA assemblies efficiently harness photogenerated electrons and holes to convert protons and isopropanol into hydrogen (H₂) and acetone, respectively, achieving a nearly 1:1 ratio of the reduction product (H₂) to the oxidation product (acetone).