Artificial Chloroplast Nanoarchitectonics through Liquid-Liquid Phase Separation Enables Recycled and Enhanced Photosynthesis.

Biomimetic supramolecular assembly offers a potent strategy to achieve artificial photosynthesis with higher efficiency. We constructed a polyoxometalate (POM)-based artificial chloroplast through liquid-liquid phase separation (LLPS), which efficiently mimics the photocatalytic water oxidation process. Such an architecture shows a greatly enhanced oxygen evolution rate with excellent recyclability in a confined space. To be specific, mixing a positively charged polyelectrolyte with a negatively charged sacrificial electron acceptor (SEA) in a stoichiometric manner creates coacervate droplets so as to entrap POM molecules. A microreactor with an obviously wrinkled structure is assembled. Spontaneously, a homogeneous-to-heterogeneous transformation enables POM to possess excellent recyclability, reusability, and structural stability occurring in an artificially designed microreactor. As a consequence, the efficiency of photocatalytic water oxidation to produce O2 is remarkably improved compared to that of POM in the homogeneous state. This work opens a new avenue to integrate multiple functionalized components into one system to improve photosynthetic performance, which holds great potential in real applications.