采用配体交换法制备贵金属纳米粒子修饰电极的研究

摘要

恒择8个碳链长度的烷基双硫醇分子在电极表面自组装构筑Au-SHSAM模板，然后将由弱保护剂四辛基溴化铵(TOAB)稳定的小尺寸Au、Ag、Pd和Pt纳米粒子通过纳米粒子与电极上巯基之间的强相互作用(M-S)将其表面的弱保护剂 TOAB 替换的方式，成功实现了贵金属纳米粒子在巯基模板电极表面的自组装，利用循环伏安法(CV)和扫描隧道显微镜(STM)对纳米粒子怱饰电极在H2SO4溶液中的电化学行为以及纳米粒子在电极表面的形貌进行了表征，发现可以通过调节浸泡时间控制纳米粒子在电极表面的覆盖度。该方法新颖、简单而且具有一定的普适性。%The template electrode of Au-SHSAM modified by dithiol which with 8 carbon alkyl chain length was self-assembled, and then little size nanoparticles of Au, Ag, Pd, Pt which protected by the weak protective agent, tetraoctyl bromide (TOAB), were anchored on the electrode surface to obtain stable nanoparticles modified electrode by ligand exchange method, due to the strong interaction between the dithiol group on the electrode and nanoparticles (M-S) ,The electrode modified by dithiol would replace weak protective agent (TOAB) which on nanoparticles surface. The electrochemical behavior in H2SO4 solution and the morphology of nanoparticles on dithiol template electrode surface was characterized by cyclic voltammetry(CV) and scanning tunneling microscopy (STM). Then we found that the coverage of nanoparticles on the electrode surface could be controlled by adjusting soak time in nanoparticles collosol. The approach is original, simple, and has certain universal.