1. Department of Plasma Engineering, Korea Institute of Machinery and Materials, 156 Gajeongbuk-Ro, Yuseong-Gu, Daejeon, 305-343, South Korea
2. Heesung Catalysts Corp., 1251-6, Jungwang Dong, Shiheung City, Kyungki-Do, 429-450, South Korea
3. Department of Chemistry, Sungkyunkwan University, 2066 Seobu-ro, Suwon 16419, South Korea