钛基氧化物电极的分形维数和电催化性能

分形几何学是近十几年来发展起来的新的数学理论，它对研究自然科学中的不规则几何行为具有独特的优势，尤其对材料的表面结构与性能研究有着重要的理论和实际意义。多相催化反应的一个显著特征就是在整个反应的一个显著特征就是在整个反应过程中都存在着反应界面，而界面的结构性质对反应过程有重要的影响。十几年前，有关这类界面的研究几乎都基于欧氏几何模型，在简单情况下视之为平面，在较复杂的情况下视之为曲面，即总是把表面视为二维面，但在很多情况下，这种做法与实际情况并不相符，例如，催化剂是多孔的，表面极不规则，存在各种晶体缺陷，而这些缺陷一般又是活性中心的集中处，面对这类粗糙的表面，经典的夫整几何学已显得无能为力，近年来，由Mandelbrot建立起来的分形几何学给人们解决诸多粗糙表面的复杂问题提供了新的途径和思路，本文计算了几种电极材料的表面分形维数，并对其催化性能进行了讨论。

Fractal Dimensions of Ti-Supported Oxide Electrodes and Their Electrocatalytic Properties

Several Ti-supported oxide anodic materials are prepared bythermal decompositi on method and the anodic kinetic parameters (a,b,i0) are determined in 1m ol/L H2SO4 solution. The SEM photographs of the electrodes are scanned and saved as a BMP image file, from which a three-dimensional space with graph and g rey scale is obtained. Then the fractal dimension of the electrodes is calculated by using the formula DB(F)=logNδ(F)/-logδ and acalc ulation program. The electrocatalytic performance of the electrodes is discussed combining with the fractal dimension and kinetic parameters. The influences of the electrode composition on the kinetic parameters are also discussed according to the dual barrier model and mechanism of the oxygen evolution at oxide anodes . The results show that the larger fractal dimension of the electrodes is, the better electrocatalytic activityis.