1. Department of Applied Physics and Material Science, California Institute of Technology, Pasadena, California 91125, United States
2. Joint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, California 91125, United States
3. Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
4. Department of Chemistry, University of Cambridge, CB2 1EW Cambridge, United Kingdom
5. Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Institute for Solar Fuels, D-14109 Berlin, Germany
6. Department of Physics, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
7. Fraunhofer Institute for Solar Energy Systems ISE, D-79110 Freiburg, Germany
8. Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, United States