SERS光谱及电化学法研究硫脲和苯基硫脲对铁的缓蚀作用

SERS AND ELECTROCHEMISTRY STUDIES ON THE INHIBITION OF THIOUREA AND PHENYL THIOUREA ON IRON

运用过电位沉积技术沉积一薄层铁到活化的银电极表面制得薄层铁电极，通过表面增强拉曼散射光谱和电化学方法研究了硫脲和苯基硫脲在该电极表面的Ｅ－Ｉ曲线和ＳＥＲＳ谱。结果表明，在０．１ｍｏｌ／ＬＫＣｌ溶液中，上述两种缓蚀剂均能吸附在铁的表面，对铁起缓蚀作用，二者在铁表面的吸附模式基本相似，系通过分子中的硫原子与金属铁作用。苯基硫脲由于硫原子带有更多的负电荷，更易与铁作用，其苯环因位阻效应而远离金属表面排列，形成较紧密的吸附层，因而其对铁的缓蚀效果更好。

An iron electrode was obtained by depositing a thin layer of iron on active silver electrode with overpotential deposition method.The E～I curve and SERS spectra of thiourea(TU) and phenyl thiourea(PTU) adsorbed on the iron electrode surface were studied by means of electrochemistry and SERS spectroscopy.The results showed that both TU and PTU can be adsorbed on the iron electrode surface and the inhibition of PTU is better than TU in 0 1mol/L KCl solution.The adsorption mode of TU and PTU is similar in the interaction of S atom and iron surface.The cause of better inhibition effect of PTU lies in that the PTU can be more easily adsorbed on iron electrode because of more negative charge in its S atom and benzene ring in PTU is arranged away from the iron surface to form a rather compact adsorption layer due to steric hindrance.