Chain Length Effect on Photocurrent from Polymethylene-Linked Porphyrins in Self-Assembled Monolayers
Chain Length Effect on Photocurrent from Polymethylene-Linked Porphyrins in Self-Assembled Monolayers
复制标题
自组装单分子层中聚亚甲基连接的卟啉的链长对光电流的影响
作者：
H. Imahori;Hiroyuki Norieda;Shin;K. Ushida;H. Yamada;T. Azuma;and Koichi Tamaki;Y. Sakata
制备了一系列两端含有卟啉的烷基间隔基的二硫化物，研究了间隔基长度对金电极表面自组装膜（SAMs）界面结构和光电化学性能的影响.使用紫外可见吸收光谱、循环伏安法和光电化学研究研究了自组装膜的结构。这些测量表明，随着间隔物长度的增加，自组装膜倾向于在金电极上形成高度有序的结构。在甲基紫精作为电子载体存在下，使用改性的Au和Pt电极进行光电化学研究。光电流随着间隔基长度的减小而显著降低，表明对于激发的卟啉存在两种竞争性失活途径，即，电极和电子载体的猝灭。
Disulfides, with a series of alkyl spacers containing porphyrins at both ends, were prepared to evaluate the effect of the spacer length on the interfacial structure and photoelectrochemical properties of self-assembled monolayers (SAMs) on a gold electrode. The structure of the SAMs was investigated using UV−visible absorption spectroscopy, cyclic voltammetry, and photoelectrochemical studies. These measurements showed that as the length of the spacers increases, the SAMs tend to form a highly ordered structure on the gold electrode. Photoelectrochemical studies, using modified Au and Pt electrodes, were carried out in the presence of methyl viologen as an electron carrier. The photocurrents decrease dramatically with a decrease in the spacer length, indicating that there are two competitive deactivation pathways for the excited porphyrin, i.e., the quenching by the electrode and electron carrier.