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

Abstract

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, <b>CPPA</b>, to form a giant-vesicle-like (GVL) architecture, termed <b>GVL-QDs@CPPA</b>. The <i>in situ</i> generation of osmotic pressure during the self-assembly of QDs onto swollen <b>CPPA</b> 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 <b>CPPA</b> 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, <b>GVL-QDs@CPPA</b> 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).