(447g) Synthetic Photoelectrochemical Complexes for Solar Energy Conversion That Self-Regenerate

Authors: 
Strano, M., Massachusetts Institute of Technology
Boghossian, A. A., Massachusetts Institute of Technology
Ham, M., Massachusetts Institute of Technology
Jeng, E. S., Massachusetts Institute of Technology
Graff, R. A., University of Illinois at Urbana-Champaign
Heller, D. A., Massachusetts Institute of Technology
Chang, A. C., Massachusetts Institute of Technology
Mattis, A., University of Illinois Urbana-Champaign
Bayburt, T. H., University of Illinois Urbana-Champaign
Grinkova, Y. V., University of Illinois Urbana-Champaign
Zeiger, A. S., Massachusetts Institute of Technology
Hobbie, E. K., National Institute of Standards and Technology
Sligar, S. G., University of Illinois Urbana-Champaign
Wraight, C. A., University of Illinois Urbana-Champaign


Naturally occurring photosynthetic systems in plants are supported by elaborate pathways of self-repair that limit the impact of photo-damage and degradation. Despite advantages in stability and fault tolerance, synthetic photoelectrochemical systems have to date been invariably static. Herein, we demonstrate a complex consisting of two recombinant proteins, phospholipid and a carbon nanotube that reversibly assembles into a particular configuration, forming an array of 4 nm lipid bilayers housing light-converting proteins orientated perpendicular such that the hole conducting site is in close proximity to the nanotube conductor. The complex can reversibly self-assemble into this useful configuration, and disassemble to free components upon the addition of sodium cholate, over an indefinite number of cycles. The assembly is thermodynamically meta-stable and can only transition reversibly between free components and assembled state if the rate of surfactant removal exceeds about 10-5 sec-1. In the assembled state only, the complexes exhibit high photoelectrochemical activity using a dual Fe(CN)63-/ubiquinone mediator with external efficiencies near 40% that are repeatedly recoverable even after continuous cycles of disassembly and regeneration. By mimicking natural repair processes, such systems may lead to more robust and facile solar conversion systems.