HCFC-22 분해폐수 전해질이 사용된 급속 파괴 양극산화에 의한 타이타니아 나노튜브다발 분말 제조에 관한 연구

초록

TiO2 nanotube arrays have been produced by a number of manners including nanoporous alumina template method, sol-gel transcription process, and hydrothermal technique. Among them, anodization is an electrolytic process that creates a TiO2 nanotube film over a metallic Ti substrate, in particular using an electrolyte containing fluoride ions. However, when the electrolyte containing chloride or hypochlorite ions is used instead of fluoride-based electrolyte, TiO2 powders composed of nanotube bundles, which are detached from Ti substrate, are obtained via rapid breakdown anodization process. In this study, rapid breakdown anodization using a wastewater originated from thermal decomposition of HCFC-22 refrigerant is investigated. Since the wastewater contains fluoride, chloride, and nitrate ions, which is essential for anodization of Ti, TiO2 nanotubes bundle powder having a pore size less than 9 nm is successfully obtained. As the applied voltage increases, the mass production of TiO2 nanotubes bundle powder increases without affecting the geometrical properties of the individual TiO2 nanotube and TiO2 nanotubes bundle powder. In addition, it is confirmed by using an artificial electrolyte containing with or without nitrate ions that the trace concentration of nitrate ions in wastewater generated from the nitrogen plasma plays a crucial role as a catalyst, accelerating the growth of the nanotubes.