Surface analytical study of carbothermally reduced titania films for electrocatalysis application
Surface analytical study of carbothermally reduced titania films for electrocatalysis application
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DOI：
10.1016/j.electacta.2012.02.044
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发表时间：
2012-06
影响因子：
6.6
通讯作者：
C. Rüdiger;F. Maglia;Silvia Leonardi;M. Sachsenhauser;I. Sharp;O. Paschos;J. Kunze
中科院分区：
文献类型：
--
作者：
C. Rüdiger;F. Maglia;Silvia Leonardi;M. Sachsenhauser;I. Sharp;O. Paschos;J. Kunze
对碳热还原过程进行了详细的研究，研究了在750℃到1050℃之间不同的热处理温度，使阳极生长在钛板上的致密的二氧化钛薄膜转化为TiOxCy。用扫描电子显微镜(SEM)、原子力显微镜(AFM)、X射线光电子能谱(XPS)和掠入射衍射仪(GID)研究了转化前后薄膜的形貌、化学成分和晶体结构。在此基础上提出了致密的阳极二氧化钛薄膜碳热转化机理的热力学模型，表明钝化膜中的碳和氧含量随退火温度的升高而降低。用电化学阻抗谱(EIS)研究了薄膜的电学性质，发现电荷转移电阻随退火温度的升高而增大。首次对TiOxCy.上的析氢反应(HER)的研究表明，电催化性能直接取决于表面的化学、结构和电子性质，因为随着热处理温度的升高，HER的过电势向更高的值移动。这项研究对于制备导电的、电化学稳定的平坦的TiOxCy膜作为电催化研究的模型载体具有重要的意义。
A detailed investigation of the carbothermal reduction process has been performed by studying different annealing temperatures between 750 and 1050°C for the conversion of compact TiO2films grown anodically on Ti sheets to TiOxCy. The morphology, chemical composition and crystallographic structure of the films before and after the conversion have been studied with scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and grazing incidence diffraction (GID). A thermodynamic model is proposed based on these investigations for the carbothermal conversion mechanism on compact anodic titania films showing that carbon and oxygen contents in the passive film decrease with increasing annealing temperature. The electronic properties have been investigated using electrochemical impedance spectroscopy (EIS) revealing an increase in charge transfer resistance with increasing annealing temperature. First studies of the hydrogen evolution reaction (HER) on TiOxCyindicate that the electrocatalytic properties directly depend on the chemical, structural and electronic properties of the surface since the overpotential of the HER shifts to higher values for increasing annealing temperature. This study is highly important for the production and investigation of conductive and electrochemically stable flat TiOxCyfilms as model supports for electrocatalysis studies.