1. Catalonia Energy Research Institute - IREC, Sant Adria de Besòs, 08930 Barcelona, Spain
2. Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, CH-8093 Zürich, Switzerland
3. Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
4. Department of Chemical and Biological Engineering, Hong Kong University of Science and Technology, Hong Kong, China
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, 111321 Ciudad Universitaria, Bogotá, Colombia