硫酸溶液中硫脲对铁缓蚀作用的电化学和SERS研究

用表面增强拉曼散射（ＳＥＲＳ）光谱技术和电化学手段研究硫脲在硫酸体系中对铁的缓蚀作用，结果表明，硫脲对铁的缓蚀作用具有浓度极值现象。低２的硫脲通过活性点吸 抑制铁的阳极溶解，高２的硫脲参与铁伯最极溶解反应，奠定Ｌａｎｇｍｕｉｒ吸附等温式，动力学参数为ＶＴＵ＝１，ｂａ＝１１８ｍＶ，低浓度硫脲主要以平行吸附为主，高２硫脲则倾向于垂直吸附。

SERS AND ELECTROCHENICAL STUDY OF INHIBITION MECHANISM OF THIOUREA ON IRON IN H_2SO_4 SOLUTION

The inhibitive action of thiourea (TU) on the corrosion behaviour of iron was investigated in 0.5mol/L H2SO4 solution by means of SERS spectra and electrochemical measurements. TU inhibited the cathodic and anodic reactions of iron. The inhibitor effectiveness increased with its concentration, reached a maximum (at about 1.25mol/L) and then decreased. TU in low concentrations inhibited the anodic reaction of iron by adsorption on active sites; TU in high concentrations participated in the anodic reaction of iron, and followed a Langmuir-type isotherm. The corresponding kinetics parameters were VTU =l,ba=118mV. TU was adsorbed mainly parallel to iron surface at low concentrations. However, TU inclined to be perpendicular to the surface as its concentration become higher.