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利用水热法合成了钼酸盐插层锌铝铈水滑石(ZnAlCe-MoO_4 LDH),并通过单因素试验和正交试验对水热合成过程中的n(Al~(3+))/n(Ce~(3+))摩尔比、反应温度、陈化温度等工艺参数进行了优化。利用扫描电镜、X射线衍射仪、红外光谱等对ZnAlCe-MoO_4LDH的形貌和结构进行了表征,并通过电化学阻抗谱、X射线光电子能谱等技术研究了ZnAlCe-MoO_4LDH对Q235碳钢在3.5%(质量分数)NaCl溶液中的缓蚀性能和缓蚀机制。结果表明,合成的ZnAlCe-MoO_4LDH呈片层状,片层厚度约为30 nm;ZnAlCe-MoO_4LDH的最佳制备工艺条件为:n(Al~(3+))/n(Ce~(3+))摩尔比6∶1,反应温度60℃,陈化温度100℃。ZnAlCe-MoO_4LDH对碳钢在3.5%NaCl溶液中的缓蚀作用,一方面体现在ZnAlCe-MoO_4LDH层板间的MoO_4~(2-)会与溶液中的Cl~-发生离子交换,降低了溶液中的Cl~-含量;另一方面释放到溶液中的MoO_4~(2-)会与Fe~(2+)和Fe~(3+)形成钼酸盐钝化膜,且层板上释放出的Zn~(2+)和Ce~(3+)会与OH~-形成氢氧化物沉积膜,从而减缓了Q235钢在3.5%NaCl溶液中的腐蚀速率。
The molybdate intercalated ZnAlCe-MoO 4 LDH was synthesized by hydrothermal method. The effects of hydrothermal process on the formation of n (Al 3+) / n (Ce ~ (3+)) molar ratio, reaction temperature, aging temperature and other process parameters were optimized. The morphology and structure of ZnAlCe-MoO_4LDH were characterized by scanning electron microscopy, X-ray diffraction and infrared spectroscopy. The effects of ZnAlCe-MoO_4LDH on the mechanical properties of Q235 carbon steel were investigated by electrochemical impedance spectroscopy, X-ray photoelectron spectroscopy, Corrosion inhibition performance and corrosion inhibition mechanism in% (mass fraction) NaCl solution. The results show that the synthesized ZnAlCe-MoO 4 LDH is lamellar and the lamellar thickness is about 30 nm. The optimum preparation conditions of ZnAlCe-MoO 4 LDH are as follows: n (Al 3+) / n (Ce 3+) ) Molar ratio 6: 1, reaction temperature 60 ℃, aging temperature 100 ℃. The corrosion inhibition effect of ZnAlCe-MoO 4 LDH on carbon steel in 3.5% NaCl solution, on the one hand, is that the MoO 4 2- ion exchange between the ZnAlCe-MoO 4 LDH layer and Cl ~ in the solution can reduce ion exchange in the solution On the other hand, MoO_4 ~ (2-) released into the solution forms molybdate passivation film with Fe_2 and Fe_ (3+) and the released Zn 2+ and Ce 3+ formed hydroxide films with OH ~ -, which slowed down the corrosion rate of Q235 steel in 3.5% NaCl solution.