[1] Univ Calif San Diego, Dept Nanoengn, La Jolla, CA 92093 USA
[2] Univ Calif San Diego, Program Mat Sci, La Jolla, CA 92093 USA
[3] Univ Calif San Diego, Program Chem Engn, La Jolla, CA 92093 USA
[4] Univ Calif San Diego, Sustainable Power & Energy Ctr, La Jolla, CA 92093 USA