1. Electrochemical Techniques to Study Solid Materials
Fritz Scholz
Universität Greifswald
Institut für Biochemie
Lehrstuhl für Analytische Chemie und Umweltchemie
(Editor-in-Chief Journal of Solid State Electrochemistry)
Felix-Hausdorff-Straße 4, Greifswald, Germany
Tel.: +49-(0) ,Fax: +49-(0)
Copyright statement: Most of the figures and part of the text are subject to copyright restrictions, and should not be copied without permission of the copyright holders.

2. The Electrochemistry of Microparticles - 1 -

3. Composite electrodes (powder + binder + ‘carbon’) Electrography
Previous techniques to study the electrochemistry of solid materials/compounds (material that is capable of faradaic reactions)*
Compact electrodes
Composite electrodes (powder + binder + ‘carbon’)
Electrography
Paste electrodes
Voltammetry of suspended particles
Film electrodes; surface modified electrodes
Cells with solid electrolytes (classic SSEC)*
References to the historic development:
Electrochemical solid state analysis - state of the art, F. Scholz, B. Meyer, Chem. Soc. Rev. 23 (1994)
Abrasive Stripping Voltammetry - an Electrochemical Solid State Spectroscopy of Wide Applicability, F. Scholz, B. Lange, Trends Anal. Chem. 11 (1992)
3. Electrochemistry of Immobilized Particles and Droplets, F. Scholz, U. Schröder, R. Gulaboski, Springer, Berlin 2005, XIII, 290 p., ISBN:
* Solid ionic conductors (solid electrolytes) are not considered here.

4. Compact electrodes
Very suitable (even necessary!!) for corrosion studies, plating etc.
However:
Often difficult to prepare
High currents
Bad signal resolution, especially when multicomponent systems are studied
Very sensitive to surface coverage by oxidized layers
Impossible to make from (a) non-conducting materials, from (b) powder materials, (c) from precious material that is only available in very tiny amounts

5. Compact electrodes A special kind for special applications:
Pressed electrodes
Ref.: V V Slepushkin, Zh Anal Khim 1987, 42, 606
AuxE RE
Glass cylinder without bottom
Rubber ring for tightening
solution
Solid sample = working electrode

6. Composite electrodes
Frequently: powdered electroactive compound + binder + e-conductor (Carbon)
Standard technique to prepare electrodes for batteries
Advantages: Almost universally applicable
Disadvantages: - tedious preparation, - results depend strongly on preparation (pressure, binder, etc.), - needs rather larger amounts of compounds*, - needs special holders for electrodes or conductive gluing,
large amounts = large charges for complete reactions,
i.e., slow scan rates and long times for experiments!

7. Electrography
Electrography, introduced independently by A. Glazunov and H. Fritz, is an obsolete technique, however, it deserves reference, as it was a first direct electrochemical analysis of solid materials.
References:
1. H. Fritz, Z. analyt. Chem. 78, 418 (1929)
2. A. Glazunow, Chim. ind. Paris Spec. No. 1929, 425
3. Jirkovský R (1934) Mikrochemie (N.F. 9) 15:
4. Arun K. Dey, Animesh K. Ghose, and Deep K. Shukla, Mikrochimica Acta [Wien]
1981II,
Experimental arrangement in electrography: A anode, AL cathode, N mineral, p paper soaked with a reagent solution

8. Electrographic print of a nickel ore
Electrographic print of a nickel ore. The black parts represent the originally red spots of nickel dimethylglyoxime complex that have been formed where nickel ions were released into the reagent paper by oxidation of the nickel mineral
Ref: Jirkovský R (1934) Mikrochemie (N.F. 9) 15:

9. The ring oven according to Weisz
Here1, electrochemical dissolution is only used for metal ion sampling. Further analysis was performed using the ring oven technique of Weisz*.
The ring oven according to Weisz
* H. Weisz, Mikrochimica Acta, 42 (1954)
1 Arun K. Dey, Animesh K. Ghose, and Deep K. Shukla, Mikrochimica Acta [Wien] 1981II,

10. Carbon paste electrodes with organic binder
Powdered solid compound +graphite powder + organic binder (e.g. nujol)
First publication:
T. Kuwana and W. G. French, Anal Chem, 1964, 36, 241
Soviet Union / Russia:
Ol’ga Al’fredovna Songina, Anna Zalmanovna Brainina, Nina Fyodorovna Zakharchuk

11. Carbon paste electrodes with organic binder
Spectrum of the standard substances for the Ga-As-0 system obtained by cyclic voltammetry
V. I. Belyi, T. P. Smirnova, N. F. Zakharchuk: Appl Surf Sci 1989,39, 161

12. Carbon paste electrodes with organic binder
General properties:
Easy to prepare, but usually the pastes do not keep well and c hange their properties with time
Organic binder* may form a film on the sample particles (possible inhibition of electrode reactions; sometimes also beneficial)
* Typical binders are Nujol (as used in infrared spectroscopy), and
other paraffin oils

13. Carbon paste electrodes with an aqueous electrolyte binder
Powdered solid sample + graphite powder + aqueous electrolyte binder
General properties:
Easy to prepare
Aqueous binder may react with solid particles (mostly undesirable, however, this may even enhance the electrochemical response)
(Many contributions from P. Sánchez-Batanero, Valladolid, Spain)

14. Carbon paste electrodes with an aqueous electrolyte binder
M. Lamache, D. Bauer: Anal Chem , 1979,51, 1320

15. Voltammetry of suspended particles
Suspensions of micro-particles
Colloidal suspensions
General properties:
Strongly affected by surface charge of particles and electrode charge
No theory, no clear understanding, lack of experimental data

16. Voltammetry of suspended particles -Suspensions of micro-particles -
Laitinen and Kolthoff have studied the electroactivity of silver halide suspensions:
Micka has performed systematic studies of the polarography of suspended particles:

17. Voltammetry of suspended particles -Suspensions of micro-particles -

18. Voltammetry of suspended particles -Suspensions of micro-particles -
Dausheva and Songina have discussed the stability of the electrolyte film at the electrode in dependence on the electrode potential. They have assumed that only around the pzc this film is fragile enough to allow impinging particles penetrating it and contacting the metal surface allowing electron transfer. The same authors have experimentally shown that mercury(I) iodide particles strongly adhere at a mercury electrode only in the vicinity of the pzc.

19. Voltammetry of suspended particles -Suspensions of micro-particles -
M. R. Dausheva, O. A. Songina: Russian Chem. Rev. 42 (1973)

20. Particle, or gas bubble, or droplet
Adhesion and wetting as potential dependent phenomena
(electrowetting)
The surface tension of the layer of solution between the particle and the electrode (and therefore also the force to separate that film) is proportional to the square root of the potential difference E between the electrode and the solution:
(Lippmann equation)
electrode
Particle, or gas bubble, or droplet
Minimum of energy to separate the film by penetration of a particle E
liquid film
pzc

21. Ольга Альфредовна Сонгина
( , Санкт-Петербург – , Алма-Ата)
Ol‘ga Alfredovna Songina
(April 17, 1901 Saint Petersburg, Russia –
May 5, 1989, Alma-Ata (now Almaty, Kazakhstan)
“Songina –– A pioneer of electrochemical solid state analysis, and Yevgeniya Nikolayevna Varasova –– A pioneer of polarography”
F. Scholz:
J. Solid State Electrochem. 17 (2013) 1493–1504

22. (?)

23. Iosif Vladislavovich Songin (Ol’ga Al’fredovna Songina’s husband)
The expulsion of O. A. Songina from Leningrad was part of the repression against her husband I. V. Songin. He was born in 1894 in Rostov-on-Don as the son of Vladislav Osipovich Songin who was the director of the “Sankt Petersburg Metal Factory” (the later “Leningrad Metal Factory”) from 1911 to Iosif V. Songin was of Polish origin, which, most probably, was one of the reasons for the repression in 1937, as he was accused with two others1 of being a member of a “counterrevolutionary Polish nationalistic group”. Ethnic Poles suffered disproportionally to their share in the overall population. According to the KGB files, I. V. Songin had declared (most likely when he was arrested in 1937) that his father V. O. Songin was a nobleman (in Russian ‘dvoryanin’). He was arrested October 4, 1937, sentenced to death on November 22, 1937 and executed on November 27, 1937! In a handwritten CV, dated April 12, 1959, O A. Songina mentions: “In 1957, I received the information that my husband died in January 1942 in a camp; and in August of the same year (1957), my husband was postmortem rehabilitated (reference 31/VIII-57, no. 6202) of the military tribunal of the Leningrad Military District.”
1 Konstantin Stanislavovich Olevskiy (born 1901 in Tbilisi, arrested November 23rd 1937, sentenced to death on December 15th 1937 and executed on Dec. 20th 1937) and Romual’d Romual’dovich Czerwiński (born 1909 in Sankt Petersburg, arresed September 2nd 1937, sentenced to death on Oct. 1st 1937 and executed
on October 6th 1937)
Iosif Vladislavovich Songin
(Ol’ga Al’fredovna Songina’s husband)

24. O. A. Songina in 1961 together with her students
O. A. Songina in 1961 together with her students. First row from left to right: Gena Makarov, Sonya Sinickaya, Ol’ga Al’fredovna Songina, Anya Yermenko and Nadiya Sharipova. Second row from left to right: Vadim Grigor’evich Barikov, Zoya Borisovna Rozhdestvenskaya, Olya Enyutina, Mariyam Rakhimovna Dausheva and Andrey Brandt (Courtesy of M. R. Dausheva)

25. Voltammetry of suspended particles - colloidal suspensions -
First observation of a voltammetric signal of a colloidal solution:
Majer V. (1943) Chem listy 37: : colloidal iron(III) hydoxide
Voltammetric signals of colloidal suspensions of Sn, Ti, and Ti-Fe hydroxides
have been reported by M. Heyrovský, however, that are all indirect reductions
caused by hydrogen:

26. Detection of adhesion and conversion signals of liposomes on mercury electrodes
Publications of the Scholz group on vesicle adhesion
Electrochem. Commun. 4 (2002)
J. Phys. Chem. B 109 (2005)
Langmuir 22 (2006)
Langmuir 23 (2007) 8650
Bioelectrochem. 74 (2008)
Bioelectrochem. 74 (2008)
Israel J. Chem. 48 (2008)
J. Solid State Electrochem. 13 (2009)
J. Solid State Electrochem. 13 (2009)
J. Solid State Electrochem. 15 (2011) 1699–1702
Angew. Chem. Int. Ed. 50 (2011) 6872 –6875
J. Electroanal. Chem. 671 (2012) 33–37
J. Solid State Electrochem. 16 (2012)
“Electrochemistry of adhesion and spreading of lipid vesicles on electrodes” V. Agmo Hernández, U. Lendeckel, F. Scholz, Series "Modern Aspects of Electrochemistry”, Vol. 56, Editors C. G. Vayenas, R. E. White; Volume “Applications of Electrochemistry in Medicine“ Editor M. Schlesinger, Springer, New York, 2013, pp

27. Detection of adhesion and conversion signals of solid nanoparticles at solid electrodes
Detection of the adhesion events of dispersed single montmorillonite particles at a static mercury drop electrode
F. Scholz, D. Hellberg, F. Harnisch, A. Hummel, U. Hasse
Electrochem. Commun. 6 (2004)

28. Detection of adhesion and conversion signals of solid nanoparticles at solid electrodes
Detection of the adhesion events of dispersed single montmorillonite particles at a static mercury drop electrode
F. Scholz, D. Hellberg, F. Harnisch, A. Hummel, U. Hasse
Electrochem. Commun. 6 (2004)

29. Detection of adhesion and conversion signals of solid nanoparticles at solid electrodes
Detection of the adhesion events of dispersed single montmorillonite particles at a static mercury drop electrode
F. Scholz, D. Hellberg, F. Harnisch, A. Hummel, U. Hasse
Electrochem. Commun. 6 (2004)

30. Detection of adhesion and conversion signals of solid nanoparticles at solid electrodes
Reproduced from [5]
[1] Cheng W. Zhou X-F, Compton RG (2013) Angew Chem Int Ed 52:12980–12982
[2] Stuart EJE, Rees NV, Cullen JT, Compton RG (2013) Nanoscale 5:174–177
[3] Zhou Y-G, Rees NV, Compton RG (2014) Phys Chem Chem Phys 15:761–763
[4] Tschulik, K, C Batchelor-McAuley, Toh H-S, Stuart EJE, Compton RG (2014) Phys Chem Chem Phys 16:616–623
[5] Ellison J, Tschulik K,Stuart EJE, Jurkschat K, Omanovic D, Uhlemann M, Crossley A, Compton RG (2013) ChemistryOpen 2:69–75

31. Detection of adhesion and conversion signals of solid nanoparticles at solid electrodes
Tschulik, K, C Batchelor-McAuley, Toh H-S, Stuart EJE, Compton RG (2014) Phys Chem Chem Phys 16:616–623

32. Voltammetry of Immobilized Microparticles (Abrasive Stripping Voltammetry)
Mechanical immobilization of microparticles on the surface of suitable electrodes
Introduced:
A New Procedure for Fast Electrochemical Analysis of Solid Materials
F. Scholz, L. Nitschke, G. Henrion: Naturwissenschaften 76 (1989) 71
A New Technique to Study the Electrochemistry of Minerals
F. Scholz, L. Nitschke, G. Henrion, F. Damaschun: Naturwissenschaften
76 (1989)

33. Voltammetry of Immobilized Microparticles (Abrasive Stripping Voltammetry)
A.Doménech Carbó, J. Labuda, F. Scholz: Pure and Appl. Chem. 85 (2013) 609–631

34. Voltammetry of Immobilized Microparticles (Abrasive Stripping Voltammetry)
Reviews:
F. Scholz, B. Lange: Trends Anal. Chem. 11 (1992)
F. Scholz, B. Meyer: Chem. Soc. Rev. 23 (1994)
T. Grygar, F. Marken, U. Schröder, F. Scholz: Coll. Czech. Chem. Commun. 67 (2002)
A.Doménech Carbó, J. Labuda, F. Scholz: Pure and Appl. Chem. 85 (2013) 609–631
Book chapters:
“Voltammetry of Solid Microparticles Immobilized on Electrode Surfaces”
F. Scholz, B. Meyer: Electroanalytical Chemistry, A Series of Advances,
A. J. Bard, I. Rubinstein (Edts.), Vol. 20, 1998, pp.1, Marcel Dekker, Inc., New York
“Electrochemical studies of solid compounds and materials”
D. A. Fiedler, F. Scholz, Chapter II.8, in “Electroanalytical Methods – Guide to Experiments and Applications”; F. Scholz (Ed.); Springer, Berlin, 2005, 2nd printing, ISBN
Book:
“Electrochemistry of Immobilized Particles and Droplets”
F. Scholz, U. Schröder, R. Gulaboski, Springer, Heidelberg, Berlin 2005, XIII, 290 p., ISBN:

35. Solid state electroanalytical chemistry (SSEAC)
A.Doménech Carbó, J. Labuda, F. Scholz: Pure and Appl. Chem. 85 (2013) 609–631

37. Three-phase electrode
Solution
Three-phase junction
Solid compound
Electron conductor, e.g. metal, graphite, etc.

38. Immobolization of Microparticles

39. The Electrochemical Cell

40. Cleaning the Electrode

41. The Electrode Paraffin Impregnated Graphite Electrode (PIGE)
Pyrolytic Graphite Electrode
Highly Oriented Pyrolytic Greaphite Electrode
Glassy Carbon Electrode
Metal (Pt, Au) Electrode
Pencil Leads
Boron Doped Diamond Electrodes
Composite Electrodes

42. Paraffin Impregnated Graphite Electrodes
These electrodes consist of high purity graphite rods whose pores are filled with paraffin in order to prevent high background currents and the spoiling of the electrode by ingression of solution.
To prepare PIGE‘s, paraffin (melting point between 56 and 70 °C or higher) is melted in a closed vessel in a water bath. The graphite rods are added to the melt and the vessel is carefully evacuated. The melt remains under vacuum until no more bubbles evolve from the rods. It is then returned to ambient pressure which leads to a complete penetration of the rod by the paraffin. The rods are removed from the melt before the Paraffin solidifies and are placed onto filter paper in order to remove excess paraffin.

43. Three-phase electrodes Three-phase junction line
Scheme of some of the possible electrochemical reactions of solid particles immobilized on a solid electrode and in contact with an electrolyte solution
Three-phase electrodes
Three-phase junction line
Insertion electrochemistry = electron and ion transfer between 3 phases

44. Three-phase junction line
Electrolyte solution
Electroactive solid particle
Electronic conductor (support)

46. Insertion electrochemistry
Electroactive solid compound
Electrolyte solution
Electronic conductivity (large)
Reaction front
Ionic conductivity (small)
Electronic conductor (support)

47. Insertion electrochemistry
Electroactive solid compound
Electrolyte solution
Electronic conductivity (small)
Reaction front
Ionic conductivity (large)
Electronic conductor (support)