(北京科技大學(xué) 材料科學(xué)與工程學(xué)院 腐蝕與防護(hù)中心，北京 100083)
摘 要: 通過掃描電鏡、X射線衍射、陽(yáng)極極化曲線和加速壽命等試驗(yàn)研究基體噴砂預(yù)處理對(duì)Ti/IrO2·Ta2O5陽(yáng)極的表面形貌、析氧電催化活性和壽命的影響。結(jié)果表明：鈦陽(yáng)極表面形貌受噴砂工藝壓力和磨料粒度的影響，噴砂壓力對(duì)鈦基體的粗糙度Ra貢獻(xiàn)大，在磨料粒度相同的情況下，粗糙度近似與壓力成正比；基體的粗糙度Ra的不同影響涂層的表面形貌和晶粒尺寸，隨著Ra增大，涂層中活性組元IrO2的晶粒得以細(xì)化；基體的粗糙度Ra值對(duì)晶粒形核生長(zhǎng)、陽(yáng)極的電催化活性和壽命的影響是重要的，但并非Ra越大，晶粒析出越多，直接的影響因素是基體表面微觀凸起的數(shù)量；表面微觀凸起的數(shù)量影響到陽(yáng)極的電催化活性，IrO2晶化的量越多，析氧電流就越大；基體的粗糙度Ra并非與鈦陽(yáng)極的壽命成正比；基體的粗糙度Ra為3.6 μm的陽(yáng)極析氧催化活性和壽命分別提高7%~36%和63%~72%，兼具最佳的析氧催化活性和最長(zhǎng)的壽命。
關(guān)鍵字: 鈦陽(yáng)極；噴砂；析氧；催化活性；加速壽命；粗糙度
（Corrosion and Protection Center, School of Materials Science and Engineering,
University of Science and Technology Beijing, Beijing 100083, China）
Abstract: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 3.6 μm shows the best catalytic activity for oxygen evolution and the longest service life, which are improved by 7%~36% and 63%−72%, respectively.
Key words: titanium anode; sand-blasting; oxygen elution; electrocatalytic activity; accelerated life; roughness
