TiO2纳米管阵列膜的制备及对304不锈钢的光生阴极保护效应

应用电化学阳极氧化法在Ti表面构筑不同的TiO2纳米管阵列膜。采用XRD、SEM、XPS表征薄膜的结构、形貌和组成。通过电化学阻抗谱及电位随时间变化的测试,考察TiO2薄膜的光生阴极保护效应。结果表明薄膜主要由锐钛矿型的TiO2纳米管阵列组成,当304不锈钢耦连于紫外光照下的TiO2薄膜电极时,其界面反应电阻变小,电极电位显著降低,说明TiO2纳米管薄膜能够对不锈钢产生良好光生阴极保护效应,特别是掺Fe的TiO2薄膜在光照时可使不锈钢电位降低约450mV,而且在暗态时也能较长时间保持对不锈钢的阴极保护作用。

Study on the TiO2 nanotube array films for photocathodic protection of 304 stainless steel

Highly ordered TiO2 or Fe doped TiO2 nanotube films were prepared on the surfaces of pure titanium by an anodic oxidation method in 0.5wt% NH4F+1.0mol/L(NH4)2SO4,0.5wt% HF and 0.5wt% HF+0.10mol/L Fe(NO3)3 solutions,respectively.The morphology,the structure and composition of the as-prepared TiO2 nanotube films were characterized by SEM,XRD and XPS.In the meantime,the performances of photocathodic protection of the films were evaluated by electrochemical measurements.The results indicated that the films mainly consisted of anatase TiO2.When 304 stainless steel in a 0.5mol/L NaCl solution was coupled to the TiO2 film in a 0.4mol/L Na2SO4 solution,its interfacial reaction resistance and the electrode potential decreased steeply under ultraviolet illumination,which indicated that TiO2 nanotube arrays could produce a good photocathodic protection effect for the stainless steel.Especially the potential of 304 stainless steel coupled to the Fe doped TiO2 film decreased by 450mV under illumination,and remained lower than the corrosion potential after the light source was cut off for about 6h,showing a better photocathodic protection effect.