(H4N)2S对电合成CoO/聚苯胺复合膜腐蚀性能的影响
Effects of adding (H4N)2S on corrosion performance of electro synthesized CoO/PANI composite coating

在CoSO4-C6H7N-H2SO4混合液中，采用恒电位法合成了CoO/聚苯胺（PANI）复合膜，研究了添加剂（H4N）2S对CoO/PANI复合膜的影响。通过电化学测试技术、SEM、XRD和加速腐蚀试验等方法对CoO/PANI复合膜的微观形貌及耐腐蚀性能进行分析。结果表明，合成的CoO/PANI复合膜中，CoO以晶体形式存在，（H4N）2S的加入改变了CoO/PANI复合膜膜层的微观形貌，由不致密不规则的片状结构转变为均匀致密规则的片状一体结构，（H4N）2S加入量过大导致（H4N）2S-CoO/PANI复合膜表面出现少量孔洞；未添加（H4N）2S的CoO/PANI复合膜自腐蚀电流密度为7.079×10-6 A/cm2，自腐蚀电位为-0.545 V，添加0.3 g/L的（H4N）2S后，（H4N）2S-CoO/PANI复合膜自腐蚀电流密度达到7.943×10-7 A/cm2，自腐蚀电位达到-0.314 V，极化电阻为6 426.8 Ωcm2，经过10% HCl点滴腐蚀时间达478 s，中性盐雾实验56 h未见锈蚀，（H4N）2S显著提高了CoO/PANI复合膜的耐腐蚀性能。 The CoO/polyaniline (PANI) composite coatings were synthesized in the electrolyte of CoSO4-C6H7N-H2SO4 mixture by means of constant potential method. The effect of (H4N)2S on the CoO/PANI composite coating was studied, and corrosion resistance and microstructure of the CoO/PANI composite coatings were analyzed by combining electrochemical testing technology, SEM, XRD and accelerated corrosion tests. The results show that the CoO exists in the form of crystal in the CoO/PANI composite coatings. With the loading of (H4N)2S, the microstructure of the CoO/PANI coatings changes from irregular thin lamellar morphology into uniform dense contiguous lamellar morphology, when more (H4N)2S was added, a small amount of holes appear on the surface of the (H4N)2S-CoO/PANI composite coating. Self-corrosion current density of CoO/PANI composite film without (H4N)2S is 7.079×10-6 A/cm2, and self-corrosion potential is -0.545 V. After 0.3 g/L (H4N)2S is added, self-corrosion current density of the (H4N)2S-CoO/PANI composite coating is 7.943×10-7 A/cm2, corrosion potential is -0.314 V, polarization resistance is 6 426.8 Ωcm2, corrosion time of 10% HCl drip reaches 478 s, and no rust is observed after 56 h of neutral salt spray test. Addition of (H4N)2S has obvious effects on corrosion resistance of the (H4N)2S-CoO/PANI composite coatings