1. Nano Chemical Eng. Department, Shiraz University, Shiraz, Iran
2. Chemistry Department, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia
3. Advanced Materials Research Group, Center of Hydrogen Energy, Universiti Teknologi Malaysia, Kuala Lumpur 54100, Malaysia
4. Department of Chemical Engineering, 313 Snell Engineering Center, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA