Yoon Sung Nam¹, Andrew P. Magyar², Daeyeon Lee³, Jin-Woong Kim³, Dong Soo Yun², Heechul Park², Thomas S. Pollom, Jr¹, David A. Weitz^3,4 & Angela M. Belcher^1,2

Over several billion years, cyanobacteria and plants have evolved highly organized photosynthetic systems to shuttle both electronic and chemical species for the efficient oxidation of water¹. In a similar manner to reaction centres in natural photosystems, molecular² and metal oxide³ catalysts have been used to photochemically oxidize water. However, the various approaches involving the molecular design of ligands⁴, surface modification⁵ and immobilization^{6, 7} still have limitations in terms of catalytic efficiency and sustainability. Here, we demonstrate a biologically templated nanostructure for visible light-driven water oxidation that uses a genetically engineered M13 virus scaffold to mediate the co-assembly of zinc porphyrins (photosensitizer) and iridium oxide hydrosol clusters (catalyst). Porous polymer microgels are used as an immobilization matrix to improve the structural durability of the assembled nanostructures and to allow the materials to be recycled. Our results suggest that the biotemplated nanoscale assembly of functional components is a promising route to significantly improved photocatalytic water-splitting systems.

1.Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
2.Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
3.School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA 4.Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA

Correspondence to: Angela M. Belcher^1,2