扫描电化学显微镜对铁自组装膜的电化学表征

ELECTROCHEMICAL CHARACTERIZATION OF SELF-ASSEMBLED MONOLAYERS ON IRON SURFACE BY SECM

用扫描电化学显微镜(SECM)的线扫描的方法研究咪唑啉分子吸附在铁的表面形成的自组装单分子膜(SAMs).采用恒高度工作模式,用基底产生/探头收集的原理探讨发生在探头针尖与基底间隙的化学动力学过程和对表面浓度进行检测.空白的铁电极和组装咪唑啉的铁电极在0.1 mol/L HClO4的峰电流的值分别是-1.67165e-9A和-2.146e-10A.结果表明,组装咪唑啉分子后探头具有更低的电流,其原因在铁电极表面形成的SAMs膜抑制了电极在溶液中发生的氧化还原反应,阻碍了电荷转移过程,抑制了铁基底的溶解.

The performance of corrosion inhibition of self-assembled monolayers （SAMs） of imidazoline formed on iron substrate was characterized by means of scanning electrochemical microscopy （SECM）. The line scanning on the iron surface using SECM may be used to investigate the high graphics of SAMs on electrodes through detecting the values of Faraday current on the tip. The experiments were performed at selected heights of the microelectrode above the iron substrate. The substrate generation/tip collection experiment （SG/TC） is then performed. The values of the tip current of peaks on the bare iron electrode and on the one modified with SAMs in 0. 1 mol/L HC104 were - 1. 67165e - 9Amps and - 2. 146e - 10Amps ,respectively. The results also showed that the values of tip current of peak decreased when iron substrate was modified with SAMs. The reason may be that the SAMs could suppress the redox reaction,in other words, the SAMs may act as a barrier for the dissolution of the substrate as well as for the process of charge transfer.