Using STM

One of the most important advances in electrochemistry in the last decade was tlie application of STM and AFM to structural problems at the electrified solid/liquid interface [108. 109]. Sonnenfield and Hansma [110] were the first to use STM to study a surface innnersed in a liquid, thus extending STM beyond the gas/solid interfaces without a significant loss in resolution. In situ local-probe investigations at solid/liquid interfaces can be perfomied under electrochemical conditions if both phases are electronic and ionic conducting and this... 

It is not easy to determine detailed properties of the tube terminations using STM or AFM. These microscopes cannot image undercut surfaces and the tip shape is convoluted with the cap shape of the nanotube. How ever, the tips may have very sharp edges... 

Can one use STM to study spillover/backspillover phenomena and to confirm the origin of electrochemical promotion The answer is positive and the experimental setup used for the first demonstration of electrochemically controlled spillover/backspillover between a catalyst-electrode (Pt) and a solid electrolyte (p"-Al203) is shown in Figure 5.48.78,79 A polished Pt(lll) single crystal (lOmmxlOmmxlmm) was mounted on an appropriately carved polycrystalline p"-Al203 sample (20mmx20mmx3mm). 

We are still years away from building molecular machines. In fact, using STM as a tool for molecular engineering has been compared to trying to build a wristwatch with a sharpened stick. 

Figure 1.6 Concept of single molecule fluorescence observation using STM.

The autocatalytic reaction mechanism apparent at low temperatures is expected to apply to catalytic hydrogen oxidation at high pressures. In addition, the above study is the first to use STM to observe the formation of dynamic surface patterns at the mesoscopic level, which had previously been observed by other imaging techniques in surface reactions with nonlinear kinetics [57]. This study illustrates the ability of in situ STM to visualize reaction intermediates and to reveal the reaction pathway with atomic resolution. 

Some atomic level studies of CdSe formation have been performed, using STM, AES and LEED [161, 162]. The structures formed by reduction of HScO, on the low index planes of Au are described in a number of papers [237, 238, 240, 241], in Section 7.2.3, and are listed in Table 2, for the low index planes of Au. 

Steps have also been observed by SPM on copper surfaces in electrochemical environments. Moffat, using STM, examined step faceting and disordering on Cu(100) caused by adsorption and desorption of chloride in solutions that did not contain copper ions [91], Also working with solutions without copper ion, Vogt et al. [92] showed that an ordered overlayer of chloride on Cu(100) reversibly stabilizes the... 

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