摘要
通过扫描电镜、X射线衍射、阳极极化曲线和加速寿命等试验研究基体喷砂预处理对Ti/IrO2·Ta2O5阳极的表面形貌、析氧电催化活性和寿命的影响。结果表明:钛阳极表面形貌受喷砂工艺压力和磨料粒度的影响,喷砂压力对钛基体的粗糙度Ra贡献大,在磨料粒度相同的情况下,粗糙度近似与压力成正比;基体的粗糙度Ra的不同影响涂层的表面形貌和晶粒尺寸,随着Ra增大,涂层中活性组元IrO2的晶粒得以细化;基体的粗糙度Ra值对晶粒形核生长、阳极的电催化活性和寿命的影响是重要的,但并非Ra越大,晶粒析出越多,直接的影响因素是基体表面微观凸起的数量;表面微观凸起的数量影响到阳极的电催化活性,IrO2晶化的量越多,析氧电流就越大;基体的粗糙度Ra并非与钛阳极的寿命成正比;基体的粗糙度Ra为3.6μm的阳极析氧催化活性和寿命分别提高7%～36%和63%～72%,兼具最佳的析氧催化活性和最长的寿命。
The effect of sand-blasting pretreatment of titanium substrate on the surface morphologies,electrocatalytic activities and service life of Ti/IrO2·Ta2O5 anodes was investigated by scanning electron microscopy（SEM） ,X-ray diffractometry（XRD） ,anodic polarization curve test and accelerated life test.The results show that the morphologies of Ti/IrO2·Ta2O5 anodes are impacted by different pressures and grain size of sand-blasting.The pressure of sand-blasting contributes more to the roughness of Ti substrates than to the grain size of sand-blasting.The roughness of Ti substrate is directly proportional to the pressure of sand-blasting with on the same grain size.The crystallite grains of IrO2 become finer with increasing roughness of Ti base.The roughness of base metal has an influence on the nucleation and growth of IrO2 crystal grain,as well as the electrocatalytic activity and service life,however,not the biggest degree of roughness results in the most precipitation of IrO2,but the quantity of micro-ridges of coatings surface also contributes to the electrochemical activities and lifetime of Ti based anodes.The more the quantity of crystallization of IrO2 is,the more the oxygen evolution is.The roughness degree is not positively correlative to the lifetime of the anode.Among the four anodes,the anode coated on Ti substrate with roughness of 3.6μm shows the best catalytic activity for oxygen evolution and the longest service life,which are improved by 7%～36%and 63%-72%,respectively.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2010年第6期1161-1169,共9页
The Chinese Journal of Nonferrous Metals
基金
国家高技术研究发展计划资助项目(2007AA05Z103)
关键词
钛阳极
喷砂
析氧
催化活性
加速寿命
粗糙度
titanium anode
sand-blasting
oxygen elution
electrocatalytic activity
accelerated life
roughness
