Highly orientated pyrolytic graphite surface

Fig. 8. STM images of RhJCO), deposited on a HOPG (highly oriented pyrolytic graphite) surface (140 x 140 A dimension under Nj).

Gewirth, A.A. and Bard, A.J. (1988). In situ scanning tunnehng microscopy of the anodic oxidation of highly oriented pyrolytic graphite surfaces. J. Phys. Chem., 92, 55663-6. 

Characterisation of these fullerene tubes was done by electro-deposition [developed by Smalley and cowoikers, see above references] which drives the snspended tnbes onto the surface of highly oriented pyrolytic graphite surface and are scanned by AFM. The molecular nature of the tubes was demonstrated by converting their CO2H groups to COCl, followed by reaction with H2N(CH2)nSH and exposure to lOnm gold particles. Gold (which reacts with SH) was only fonnd on the carboxylated fullerene tubes. 

Fan F-RF, Park S, Zhu Y, Ruoff RS, Bard AJ (2008) Electrogenerated chemiluminescence of partially oxidized highly oriented pyrolytic graphite surfaces and of graphene oxide nanoparticles. J Am Chem Soc 131(3) 937-939... 

S. Yang, P. Tsai, E. S. Kooij, A. Prosperetti, H. J. W. Zandviiet, and D. Lohse, Electrol54ically generated nanobubbles on highly orientated pyrolytic graphite surface, Langmuir, 25,1466-1474 (2009). 

Inaba, M. Siroma, Z. Funabiki, A. Ogumi, Z. 1996. Electrochemical scanning tunneling microscopy observation of highly oriented pyrolytic graphite surface reactions in an ethylene carbonate-based electrolyte solution. Langmuir 12 1535-1540. 

Because STM measures a quantum-mechanical tunneling current, the tip must be within a few A of a conducting surface. Therefore any surface oxide or other contaminant will complicate operation under ambient conditions. Nevertheless, a great deal of work has been done in air, liquid, or at low temperatures on inert surfaces. Studies of adsorbed molecules on these surfaces (for example, liquid crystals on highly oriented, pyrolytic graphite ) have shown that STM is capable of even atomic resolution on organic materials. 

FIG. 16 Current versus bias voltage for a CdS nanoparticle on the end of an STM tip. The CdS particles were formed by exposing a bilayer of cadmium arachidate on the STM tip to H2S gas. The other conducting surface is a highly oriented pyrolytic graphite electrode. The inset is a plot of differential conductance versus the bias voltage. (Reproduced with permission from Ref. 202. Copyright 1996 National Academy of Sciences, U. S. A.)... 

Savinova ER, Lebedeva NP, Simonov PA, Kryukova GN. 2000. Electrocatalytic properties of platinum anchored to the surface of highly oriented pyrolytic graphite. Russ J Electrochem. 36 (9) 952-959. 

The HOPG (highly oriented pyrolytic graphite) carbon electrode chemically modified with (5[-phenylalanine at the basal surface led to 2% ee in the reduction of 4-acetylpyridine [377]. A cathode modified with a chiral poly(pyrrole) reduced 4-methylbenzophenone or acetophenone in DMF/LiBr and phenol as proton donor to 1-phenylethanol with up to 17% ee [382]. Alkyl aryl ketones have been reduced to the corresponding alcohols at a Hg cathode in DMF/water in the presence of (1R,2S)-A,A-dimethylephedrinium tetrafluorobo-rate (DET), producing (5 )-l-phenylethanol with 55% ee from acetophenone. Cyclovoltammetry supports an enantioselective protonation of the intermediate (PhCOH(CH3)) [383]. 

In addition to ET-IR, XPS experiments performed on a graphite anode that had been cycled in various carbonate-based electrolytes also identified an alkyl carbonate species. Bar-Tow et al. characterized the surface of a highly oriented pyrolytic graphite (HOPG) that had been cycled in LiAsEe/EC/DEC and found the C Is signal located at 289 eV, which had been... 

---