1. Chemistry and Nanoscience Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
2. Energy Conversion Group, Energy Technologies Area, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
3. Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
4. Colorado School of Mines, Golden, Colorado 80401, United States
5. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
6. Argonne National Laboratory, Lemont, Illinois 60439, United States