涂液浓度对IrTaSnSb钛基氧化物阳极析氯活性的影响

The Effect of Precursor Concentration on Chlorine Evolution Properties of IrTaSnSb Metal Oxide Anode

采用热分解法及不同浓度涂液制备了IrTaSnSb钛基阳极,使用扫描电镜观察阳极微观表面形貌,采用电化学方法研究了析氯活性,并测试了电流效率和强化电解寿命。结果表明,不同涂液浓度制备的阳极表面形貌存在明显差别,导致析氯活性随着涂液浓度的增大呈现先升高后降低的趋势;0.30 mol/L涂液制备的阳极电流效率最高,这是因为细小均匀的裂纹增加了涂层的真实活性表面积,提高了阳极析氯活性;在阳极涂层载涂量接近情况下,低浓度涂液制备的阳极表面较平整致密,钛基体不易被氧化生成TiO_2钝化膜,强化电解寿命最长。综合考虑,0.30 mol/L涂液制备的阳极具备较高的析氯活性和强化电解寿命,此浓度是较理想的涂液浓度。

The anode coatings for IrTaSnSb oxide were prepared with precursor solutions of different concentrations by thermal decomposition method. The surface morphology was observed by scanning electron microscopy. The chlorine evolution activity of anodes was tested by electrochemical method, and the current efficiencies in sea water at room temperature and low temperature and brackish sea water were tested. The lifetime of the IrTaSnSb anode coatings were measured by accelerated life test in H2SO4 solution. The results show that there are significant differences in the surface morphologies of the anodes prepared by precursor solutions of different concentrations, and the chlorine evolution activity of anode arises and then decreases as the solution concentration increases from 0.05 mol/L to 1.00 mol/L;the anodes prepared by 0.30 mol/L solution have the highest chlorine evolution activity, for the tiny and uniform cracks in the anode surface increase the real active surface area and improve the chlorine evolution activity;when the loadings of anode coating is close, the anode surface coated by solution of low concentration is even and dense, the surface of titanium substrate is hard to be oxidized to form TiO2 passivative film, and the anodes exhibit high life time. The anode prepared by 0.30 mol/L precursor solution shows high chlorine evolution activity and long life time, and 0.30 mol/L is an ideal concentration of precursor solution.