采用热分解法制备钛基IrO2-Ta2O5涂层阳极,钛基体经喷砂和酸蚀处理后分别在550、600、650、700和750℃下的高纯氮气气氛下进行氮化处理,研究钛基体氮化处理对IrO2-Ta2O5涂层钛阳极寿命和电催化活性的影响.结果表明:经550℃氮化处理时,钛基体表面酸蚀产生的TiH2未大量分解,同时生成钛的氮化物,表面形成一层氢化物和氮化物膜,有利于IrO2的成核和晶粒细化,IrO2-Ta2O5涂层具有多孔性特征,且电极表面析出的活性物质IrO2晶粒尺寸更小、分布更均匀,平均晶粒尺寸小于20 nm,具有较佳的电催化活性和较长的寿命,加速寿命和伏安电荷值分别达到1 066 h和68.4 mC/cm2.%IrO2-Ta2O5 coated titanium anodes were prepared by thermal decomposition, and Ti substrate were nitrogen treated at 550, 600, 650, 700 and 750 ℃ after sandblasting and acid etching. The effect of nitrogen treatment of titanium substrate on accelerated life and electro-catalytic properties of IrO2-Ta2O5 coated titanium anode were studied. The results show that, during the nitriding process at 550 ℃, the TiH2 produced by acid etching on the surface of titanium substrate is not composed in massive and forms titanium nitride. At the same time, the formed hydride and nitride film on the surface is in favor of nucleation and grain refining of IrO2. The IrO2-Ta2O5 coatings are porous and the precipitated IrO2 is smaller and more well-distributed. The average grain size of IrO2 is less than 20 nm. The IrO2-Ta2O5 coated titanium anode with the substrate nitride at 550 ℃ owned the best and electro-catalytic characteristics that the voltammetric charge is 68.4 mC/cm2 and the longest life is 1 066 h.
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