1. School of Materials Science and Engineering; Nanyang Technological University; 50 Nanyang Avenue Singapore 639798 Singapore
2. Key Laboratory of Materials Physics; Anhui Key Laboratory of Nanomaterials and Nanotechnology; Institute of Solid State Physics; Chinese Academy of Sciences; Hefei 230031 P. R. China
3. Singapore-HUJ Alliance for Research and Enterprise (SHARE); Nanomaterials for Energy and Energy-Water Nexus (NEW); Campus for Research Excellence and Technological Enterprise (CREATE); 1 Create Way Singapore 138602 Singapore