无金属酞菁、酞菁铜和酞菁锌在1 mol/L H2SO4中对Q235钢的缓蚀作用

通过失重实验、电化学测试和扫描电子显微镜研究了无金属酞菁(H2Pc)、酞菁铜(CuPc)和酞菁锌(ZnPc) 在1 mol/L H2SO4中对碳钢的缓蚀作用.结果表明，3种酞菁化合物的缓蚀能力依次为ZnPc > CuPc > H2Pc，其吸附数据均符合Langmuir等温式；它们能同时抑制碳钢在H2SO4中腐蚀的阴极和阳极过程，电化学阻抗谱显示，为变形的单容抗弧，阻抗值随酞菁化合物浓度增加而增加；表面形貌分析也证明了酞菁化合物的加入提高了碳钢的表面完整性，抑制其腐蚀；量子化学计算结果显示，随着分子的最低空轨道(LUMO)的能量升高，酞菁化合物的缓蚀能力降低.

INHIBITION EFFECT OF METAL-FREE PHTHALOCYANINE, COPPER PHTHALOCYANINE AND ZINC PHTHALOCYANINE ON MILD STEEL IN 1 mol/L H2SO4

The inhibition effect of metal-free phthalocyanine(H_2Pc),copper pthalocyanine(CuPc) and zinc phthalocyanine(ZnPc) on mild steel in 1 mol/L H_2SO_4 was investigated by weight loss,electrochemical measurement and SEM observation.The weight loss results showed that the adsorption of these compounds obeyed to Langmuir isotherm;the potentio-dynamic curves indicated both anodic and cathodic processes of mild steel corrosion in H_2SO_4 were suppressed by phthalocyanines,the Nyquist diagram expressed as a capacity semi-circle,and charge transfer resistance R_t increased with the rising of pthalocyanines concentration;the surface morphology analysis of the tested samples also proved that the integrity of steel surface was enhanced and the corrosion was inhibited when added phthalocyanines;then the result of quantum chemical caluculation showed that the inhibition efficiency of phthalocyanines decreased with the increase of LUMO energy.