Time-resolved vibrational spectroscopic study of electrode dynamics

点击翻译按钮获取中文摘要

This project aimed at to study electrode kinetics and dynamics by using fast time-resolved infrared spectroscopy. The use of surface-enhanced infrared absorption spectroscopy (SEIRAS) enabled ultrafast time-resolved study in the picosecond range. The main achievements are as follows.1.Ultrafast time-resolved IR spectrscopyDouble-layer charging with a 0.1-1 ms time constant has hampered the study of ultrafast electrode dynamics. This problem was circumvented for the first time by coupling the so-called temperature jump method with picosecond time-resolved SEIRAS. The rapid heating of the interface by a laser pulse results in the sudden change in potential through reorientaion of water.2.Technical developments in SEIRASSimple and cost-effective techniques to prepare very stable SEIRA-active thin metal film electrodes on Si and Ge prisms have been developed. These techniques significantly contributed to the success of the picosecond time-resolved IR studies mentioned above.3.Molecular sca … More le analysis of electrochemical oscillationsA variety of oscillations occur at the electrochemical interface. We investigated potential and current oscillations during formic acid oxidation on Pt by time-resolved SEIRAS and proposed a new concept that explains the oscillations without any assumptions.4.ElectrocatalysisHydrogen evolution, oxygen reduction, and anodic oxidation of C_1 molecules on Pt electrodes that constitute the basis of low temperature fuel cells were examined in detail at the molecular scale. We clearly showed for the first time that all C_1 molecules are oxidized CO_2 via formate, which totally revised the general consensus.5.Structures and functions of self-assembled monolayers (SAMs)Hydrogen bond pairing between an adenine derivative self-assembled on an Au electrode and a thimidine derivative were examined by SEIRAS as a model system of molecular recognition system. We also succeeded in fabricating new types of SAMs using triruthenium complexes. Their structures and functions were examined by SEIRAS. Less