1. Department of Chemical and Environmental Engineering; Institute Center for Water and Environment (iWater); Masdar Institute of Science and Technology, PO BOX 54224; Abu Dhabi United Arab Emirates
2. Istituto per lo Studio dei Materiali Nanostrutturati; CNR via U. La Malfa 153; 90146 Palermo Italy
3. State Key Laboratory of Photocatalysis on Energy and Environment; College of Chemistry and Chemical Engineering; Fuzhou University; Fuzhou 350002 P. R. China