| dc.description.abstract | In this study, the spatial structures of 2-Mercapto-5-benzimidazolesulfonic acid (MBIS) and 2-Benzimidazolethiol (MBI) adsorbed on Au(111) have been investigated by cyclic voltammetry (CV) and scanning tunneling microscopy (STM) in sulfuric, perchloric and hydrochloric acids, revealing the immense effects of potential controlled and molecular concentration on the adsorption configuration and surface arrangement. The effects of MBI and MBIS adsorbed on a Au(111) electrode on copper electroplating are exaamined.
First, MBIS and MBI form order molecular films, whose unit cells are (3√3 × 3√3) and (√3 × 5), as characterized by STM. The coverage of MBIS and MBI is 0.11 and 0.23. MBIS is more loosely packed on Au(111) than MBI, suggesting a greater repulsive intermolecular interaction due to the sulfonate group.
Secondly, both MBIS and MBI form the same ordered structure in sulfuric and perchloric acids, but they are disordered in hydrochloric acid. This phenomenon indicates a profound effect of anion is the adsorption of MBIS and MBI. In one experiment, where the concentration of MBIS is gradually increased in the electrolyte, the MBIS structure changes from ordered to disordered. In contrast, but the MBI structure is not affect and the structure of (√3 × 5) stays with increasingly higher concentration.
Finally, both MBIS and MBI accelerate the electrodeposition of copper on Au(111) at low molecular concentration, but slow down at high concentration. | en_US |