钴酸镧掺杂Ti/RuO_2电极材料电化学性能研究

Electrochemistry Study of LaCoO_3 Doped Ti/RuO_2 Electrodes

采用热分解法制备了不同比例钴酸镧掺杂Ti/RuO_2电极材料。通过扫描电镜(SEM)、能谱分析(EDS)、X射线粉末衍射(XRD)等分析方法表征电极涂层的物相结构与形貌特征,采用电化学测量表征电极的物理化学性能。分析表明电极涂层由不规则的颗粒组成,颗粒间有一定的孔隙,掺杂钴酸镧电极涂层含有Ti,Ru,La及Co金属元素,相结构主要为金红石相,掺杂钴酸镧电极涂层的晶粒较小,不同掺杂量对晶粒大小影响不大。电化学研究表明,电极具有典型的钌氧化物所具备的电化学性能,掺杂钴酸镧电极的电化学面积较大,电极的可逆性能得到改善。所制备的电极具有大致相同的析氧电位(1.19 V vs. SCE),随着钴酸镧掺杂量的增多,Tafel斜率依次减小,表明掺杂钴酸镧电极的活性较高,且掺杂钴酸镧后电极强化寿命得到显著提高。

In this work, LaCoO 3 doped Ti/RuO 2 electrodes were prepared by the thermal decomposition method and their physicochemical properties were characterized by scanning electron microscope (SEM), X-ray energy dispersive spectrometry (EDS), X-ray diffraction (XRD), and electrochemistry studies. Our results reveal that the electrodes’ coatings consisted of irregular particles with gaps, and that elements Ti, Ru, La and Co were the main metal elements in the coatings. XRD analyses show that the coatings were formed mainly by two phases of rutile TiO 2 and RuO 2 , and that the size of coating particles decreased when LaCoO 3 was doped. Accelerated service life tests (AST) show that the life time of LaCoO 3 doped electrodes was significantly longer that that without doping. Electrochemical properties of the prepared electrodes were consistent with those of the same traditional ruthenium oxides. These prepared electrodes had nearly the same oxygen evolution potential (1.19 V vs. SCE). The Tafel slope decreased when the amount of LaCoO 3 doped was increased, suggesting that the activity of electrodes increased with the doped amount of LaCoO 3 .