1. Guangzhou Key Laboratory for Surface Chemistry of Energy Materials, New Energy Research Institute, School of Environment and Energy, South ChinaUniversity of Technology Guangzhou 510006 China
2. Building Energy Research Group, Department of Building and Real EstateThe Hong Kong Polytechnic University Hung Hom, Kowloon Hong Kong 999077 China
3. School of Materials Science and EngineeringGeorgia Institute of Technology 771Ferst Drive Atlanta GA 30332‐0245 USA