铝箔多孔阳极氧化铝膜的低温制备及其电化学性能

以多孔阳极氧化铝(AAO)膜制备纳米材料时降低AAO膜孔径至关重要,降低电压无法达到要求,而降低氧化温度可实现这一目标。在0.4 mol/L H3PO4溶液中加入70%～80%(体积分数)1,3-丙三醇(PDO),于-10～10℃下恒压110 V阳极氧化1 h制备了多孔阳极氧化铝(AAO)膜,并在0.50 mol/L H3BO3和0.05mol/L Na2B4O7溶液中于20℃下以0.5 mA/cm2进行填孔后处理。利用SEM,EDS,XRD分析了AAO膜的表面形貌与组成,并对AAO膜填孔前后的极化曲线和交流阻抗谱进行了测试。结果表明,膜孔径随氧化温度降低而降低,80%PDO,10℃所得AAO膜的成分包括65.94%(质量分数,下同)Al,12.79%C,20.29%O和0.98%P;随氧化温度升高和PDO含量下降,AAO膜的稳定电流密度增大;随氧化温度升高,膜阻挡层厚度增大;填孔试验前AAO膜只存在一个阻挡层的相位角峰,填孔后出现两个峰,中高频段体现封闭的阻挡层特性,低频段体现的是多孔层封闭部分的特性。

Low Temperature Preparation and Electrochemical Perfor mance of Porous Anodic Aluminum Oxide Coating

1,3-propanetriol was added,at a volume fraction of 70%～80%,into 0.4 mol/L H 3 PO 4 to formulate the electrolyte for anodizing of Al foil,and then porous anodizing aluminum oxide(AAO) coating was prepared in the electrolyte at a low temperature of-10～10 ℃ and constant voltage of 110 V for 1 h.Resultant AAO coating was then sealed in the solution of 0.50 mol/L H 3 BO 3 and 0.05 mol/L Na 2 B 4 O 7 at 20 ℃ and 0.5 mA/cm 2.The morphology and composition of the AAO coating were analyzed by means of scanning electron micro scopy,energy dispersive spectrometry and X-ray diffraction.Moreover,the polarization curves and alternating electrochemical impedance spectra(EIS) of the AAO coating before and after sealing treatment were measured.It was found that the pore size of the AAO coating declined with lowering anodizing temperature,and the one obtained at a propanetriol volume fraction of 80% and anodizing temperature of 10 ℃ consisted of 65.94% Al(mass fraction,the same hereafter),12.79% C,20.29% O and 0.98% P.The stable current density of the AAO coating rose with increasing anodizing temperature and decreasing content of propanetriol,and the thickness of the barrier layer rose with increasing anodizing temperature.Besides,the AAO coating before sealing treatment showed only single EIS peak,while that after sealing showed double EIS peaks of the sealed barrier layer at moderate and high frequency regions and of the sealed porous layer at low frequency region.