本研究利用二氧化鈦溶膠-凝膠(Sol-Gel)被覆於鋼材表面，在紫外光照射下，具N-型半導體特性之二氧化鈦將扮演非犧牲陽極的角色，對鋼材實行陰極保護達到防蝕效果。首先以ITO玻璃(Indium-doping Tin Oxide 濺鍍氧化銦錫之玻璃)，測試選用之二氧化鈦膠體於紫外光照射下是否能展現光電化學特性，再將二氧化鈦膠體被覆於不鏽鋼或碳鋼基材，進行動態極化掃描試驗。相較於不鏽鋼，實驗結果顯示當二氧化鈦直接被覆於碳鋼時，其光電化學效果並不顯著。根據X光薄膜繞射儀與歐傑電子能譜儀分析結果，發現基材裡的金屬元素會擴散至被覆層；因此推測，由於基材之金屬元素擴散，破壞二氧化鈦結構，使得該觸媒失去光電化學特性。透過高溫爐預長特定的氧化膜結構再於基材表層進行被覆，能有效改善基材金屬元素擴散，提升二氧化鈦之光電化學特性，當紫外光照射時，受被覆的金屬基材會有明顯的電化學腐蝕電位及腐蝕電流密度下降。根據實驗結果表示，本研究所採用之二氧化鈦溶膠-凝膠塗覆法能大幅提升金屬鋼材之防蝕性能，在嚴酷的腐蝕環境下可以有效減緩其腐蝕速率。

Stainless steel (SS) and carbon steel (CS) are susceptible to stress corrosion cracking (SCC) in certain environments, which included the sea salt particles and chlorides. In addition, the TiO2 coating can act as a nonsacrificial anode and cathodically protect steel substrates under ultraviolet (UV) illumination. In this study the ITO glass was first used as testing substrate for the availability of photocatalytic behavior of Lab-made TiO2 solutions. Then the photocatalytic behavior of steels with TiO2 coating by using a sol-gel method was investigated to mitigate atmospheric SCC. Electrochemical analysis results revealed that the electrochemical corrosion potential (ECP) of the TiO2 coated on polished 304 SS markedly decreased compared with the TiO2 coated on polished CS in the presence of UV radiation. In addition, a specific oxide structure between the TiO2 and CS interface would enhance the ECP reduction under UV radiation because of the inhibition of other metal ions diffused into the TiO2 coating. In summary, the results indicated that TiO2 treatment in combination with UV radiation can effectively reduce the corrosion rate of 304SS and CS in atmospheric environments.

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