THE ROLE OF REDOX CHEMISTRY IN SCANNING-TUNNELING-MICROSCOPY IMAGING OF ELECTROACTIVE FILMS

被引:25
作者
SNYDER, SR
WHITE, HS
机构
[1] UNIV UTAH,DEPT CHEM,SALT LAKE CITY,UT 84112
[2] UNIV TEXAS,DEPT CHEM & BIOCHEM,AUSTIN,TX 78712
来源
JOURNAL OF ELECTROANALYTICAL CHEMISTRY | 1995年 / 394卷 / 1-2期
关键词
D O I
10.1016/0022-0728(95)04071-U
中图分类号
O65 [分析化学];
学科分类号
070302 ; 081704 ;
摘要
The dependence of tunneling current I on bias voltage V-b in scanning tunneling microscopy (STM) measurements of multilayer electroactive films is interpreted in terms of a redox mechanism involving electron transfer reactions at the STM tip\film and electrode\film interfaces. Analysis suggests that a symmetrical I-V-b response is anticipated when the molecular film is sufficiently thick (ca. 2-3 monolayers) that the electron-transfer steps at the STM tip and electrode can be considered as discrete steps in the current-carrying processes. A macroscopic two-electrode thin-layer electrochemical cell is used to mimic the response of an electrode\redox film\STM tip junction. Steady-state symmetrical I-V responses are obtained for the thin-layer cell, even when the solution initially contains only one half of an electroactive redox couple. Tunneling spectroscopic measurements, using a STM, of dry films of protoporphyrin(IX)Fe(III)Cl deposited on highly oriented pyrolytic graphite electrodes are interpreted in terms of the proposed redox mechanism.
引用
收藏
页码:177 / 185
页数:9
相关论文
共 33 条
[1]  
ANDERSON LB, 1965, J ELECTROANAL CHEM, V295, P205
[2]   FREE-ENERGY CORRELATION OF RATE CONSTANTS FOR ELECTRON-TRANSFER QUENCHING OF EXCITED TRANSITION-METAL COMPLEXES [J].
BALLARDINI, R ;
VARANI, G ;
INDELLI, MT ;
SCANDOLA, F ;
BALZANI, V .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1978, 100 (23) :7219-7223
[3]  
BEHM D, 1970, ISRAEL J CHEM, V8, P259
[4]  
BEHM RJ, 1989, SCANNING TUNNELING M, P173
[5]  
BENNETT AJ, 1975, J ELECTROANAL CHEM, V60, P125, DOI 10.1016/S0022-0728(75)80324-X
[6]   ELECTROCHEMISTRY AT A PYROLYTIC-GRAPHITE ELECTRODE - STUDY OF THE ADSORPTION OF HEMIN [J].
BIANCO, P ;
HALADJIAN, J ;
DRAOUI, K .
JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 1990, 279 (1-2) :305-314
[7]   ILLUSTRATIVE ELECTROCHEMICAL BEHAVIOR OF REACTANTS IRREVERSIBLY ADSORBED ON GRAPHITE ELECTRODE SURFACES [J].
BROWN, AP ;
KOVAL, C ;
ANSON, FC .
JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 1976, 72 (03) :379-387
[8]   CORRELATION OF ELECTRON-TRANSFER RATES WITH THE SURFACE-DENSITY OF STATES OF NATIVE AND ANODICALLY GROWN OXIDE-FILMS ON TITANIUM [J].
CASILLAS, N ;
SNYDER, SR ;
SMYRL, WH ;
WHITE, HS .
JOURNAL OF PHYSICAL CHEMISTRY, 1991, 95 (18) :7002-7007
[9]   ELECTROACTIVE POLYMERS AND MACROMOLECULAR ELECTRONICS [J].
CHIDSEY, CED ;
MURRAY, RW .
SCIENCE, 1986, 231 (4733) :25-31
[10]   FREE-ENERGY AND TEMPERATURE-DEPENDENCE OF ELECTRON-TRANSFER AT THE METAL-ELECTROLYTE INTERFACE [J].
CHIDSEY, CED .
SCIENCE, 1991, 251 (4996) :919-922