An Artificial Leaf with Patterned Photocatalysts for Sunlight-Driven Water Splitting.

Plant leaves can turn entirely absorbed light into chemical energy due to their spatially separated photosystems I and II in the thylakoid membrane that enables unidirectional Z-scheme type charge transfer between them. In artificial systems that mimic leaves, a lack of spatial and interfacial control of active units (i.e., hydrogen evolution photocatalyst/HEP and oxygen evolution photocatalyst/OEP) introduces competitive charge transfer channels between them, resulting in deficient Z-scheme type charge transfer. Herein, we demonstrate that a patterned photocatalyst sheet, namely, an artificial leaf, comprising an ordered and separated distribution of the OEP and HEP strips on a conductive substrate, achieves unidirectional Z-scheme type charge transfer as the leaves do. It represents a next-generation photocatalytic system that mimics the leaves to bring breakthrough in photocatalytic over water splitting performance with the combination of highly active HEP and OEP photocatalysts, opening up a promising avenue toward solar energy conversion by artificial photosynthesis.