Jagminas Arunas, Klimas Vaclovas, Chernyakova Katsiaryna, Jasulaitiene Vitalija
State Research Institute Center for Physical Sciences and Technology, Sauletekio Ave. 3, 10257 Vilnius, Lithuania.
Materials (Basel). 2022 Apr 6;15(7):2700. doi: 10.3390/ma15072700.
Aluminum anodization in an aqueous solution of formic acid and sodium vanadate leads to the formation of alumina/carbon composite films. This process was optimized by varying the concentrations of formic acid and sodium vanadate, the pH, and the processing time in constant-voltage (60-100 V) or constant-current mode. As estimated, in this electrolyte, the anodizing conditions played a critical role in forming thick, nanoporous anodic films with surprisingly high carbon content up to 17 at.%. The morphology and composition of these films were examined by scanning electron microscopy, ellipsometry, EDS mapping, and thermogravimetry coupled with mass spectrometry. For the analysis of incorporated carbon species, X-ray photoelectron and Auger spectroscopies were applied, indicating the presence of carbon in both the and the states. For these films, the Tauc plots derived from the experimental diffuse reflectance spectra revealed an unprecedentedly low bandgap () of 1.78 eV compared with the characteristic values of alumina films formed in solutions of other carboxylic acids under conventional anodization conditions and visible-light absorption.
在甲酸和钒酸钠的水溶液中进行铝阳极氧化会导致形成氧化铝/碳复合膜。通过在恒压（60 - 100 V）或恒流模式下改变甲酸和钒酸钠的浓度、pH值以及处理时间，对该过程进行了优化。据估计，在这种电解液中，阳极氧化条件对于形成具有高达17原子%的惊人高碳含量的厚纳米多孔阳极膜起着关键作用。通过扫描电子显微镜、椭偏仪、能谱映射以及热重分析与质谱联用对这些膜的形态和成分进行了研究。为了分析掺入的碳物种，应用了X射线光电子能谱和俄歇能谱，表明在两种状态下都存在碳。对于这些膜，从实验漫反射光谱得出的陶赫图显示，与在传统阳极氧化条件下在其他羧酸溶液中形成的氧化铝膜的特征值相比，带隙（）低至1.78 eV，这是前所未有的，并且具有可见光吸收特性。
