1. College of Materials, Fujian Provincial Key Laboratory of Fire Retardant Materials, Xiamen Key Laboratory of Fire Retardant Materials, Xiamen University, Xiamen 361005, China
2. Catalonia Institute for Energy Research (IREC), Sant Adrià de Besòs, 08930 Barcelona, Catalonia, Spain
3. ICREA, Pg. Lluis Companys 23, 08010 Barcelona, Catalonia, Spain