1. Catalonia Energy Research Institute - IREC, Sant Adria de Besòs, 08930 Barcelona, Spain
2. Department of Chemical and Biological Engineering, Hong Kong University of Science and Technology, Hong Kong, China
3. Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, CH-8093 Zürich, Switzerland
4. Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
5. Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC, and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Catalonia Spain
6. ICREA Pg. Lluis Companys 23, 08010 Barcelona, Spain
7. Departamento de Física, Universidad Nacional de Colombia, Ciudad Universitaria, 111321 Bogotá, Colombia