**Acknowledgement**

This work was supported by NAFOSTED Grant No. 104.03-2011.33, 2011. This work was supported by Laboratory for nanotechnology, Vietnam National University, Ho Chi Minh in Viet Nam. We greatly thank Kyushu University in the Global COE Program, Novel Carbon Resource Sciences for the financial support in our research and development of science and nanotechnology in Kyushu University, Japan. We greatly thank Nagoya Institute of Technology for kind supports in Japan.
