钛基IrO_2-Ta_2O_5涂层阳极电化学多孔性研究

用循环伏安法研究了不同成分及不同热分解温度所得钛基IrO2 Ta2 O5 阳极电化学活性与多孔特性。阳极的电化学活性表面积随涂层中氧化物的成分变化而呈振荡变化 ;表面活性点数目随制备温度上升而下降。当阳极中IrO2 的摩尔分数为 0 .7时 ,氧化物阳极的孔隙率达到最低值 ;孔隙率随制备温度上升而下降。

Ti/IrO_2涂层阳极热氧化处理温度的选择

结合铝的表面处理和铜的生箔对阳极的要求，针对Ｔｉ／ＩｒＯ２阳极，用热差分析、电极极化、Ｘ光衍射及强化寿命试验，研究了热氧化处理温度对阳极的热分析曲线、电极电位、相结构和强化寿命的影响。在３０％Ｈ２ＳＯ４（质量比），４Ａ／ｃｍ２，４０℃±５℃下的强化寿命实验表明：小于５００℃时，阳极的寿命受涂层的溶蚀控制。大于６００℃，阳极的破坏形式以涂层脱落为主，而涂层在５００℃～６００℃之间处理的阳极的强化寿命最长，Ｔｉ／ＩｒＯ２涂层阳极的热氧化处理温度以５００℃～６００℃为最佳。

Improvement of stability of trivalent chromium electroplating of Ti based IrO_2+Ta_2O_5 coating anodes

The preparation process and properties of the thermally prepared Ti anodes coated with IrO2+Ta2O5 was studied. The structure and morphologies of the IrO2+Ta2O5 coatings were determined by XRD and SEM. Their electrochemical properties were studied by polarization curve and cyclic voltammetry. Trivalent chromium electroplating using Ti/IrO2+Ta2O5 anodes is carried out and the results were analyzed. Results show that this anode exhibits excellent electrochemical activity and stability in sulfate electrolysis. The electrocatalytic activity is determined not only by the content of IrO2 but also the structure and morphology of the anode coatings. The electroplating results indicats that Ti/IrO2+Ta2O5 anodes have excellent capabilities and merits in improving the stability of trivalent chromium electroplating in sulfate system.