1. Department of Materials Science and Engineering, I-Shou University, Kaohsiung 84001, Taiwan
2. Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131, USA
3. Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 81148, Taiwan
4. Department of Chemical Engineering, Feng Chia University, Taichung 40724, Taiwan