It gives us pleasure in writing the Preface to this volume, in which we tried to bring together a number of stimulating and interesting people discussing physical electrochemistry. The first chapter, by Ashok Vijh, gives a remarkable account of electrochemistry as looked at from a physicist's point of view. Among the revelations of the chapter is that in a recent survey of leading areas in Science, two out of fifteen areas chosen were electrochemical and these two were the only chemical subjects chosen. In Mikhail Vorotyntsev's chapter, one finds a very modern study of the double layer, but tenuously connected with the simpler studies made in the safe harbor of mercury. In the pioneering chapter by Pons et al., one is looking at a cutting edge of electrochemistry at this time-the use of IR spectros­ copy in modes which allow the first practical determinations of the spectra of adsorbed species at the interface-an area pioneered by Pons himself. In Chapter 4, we have reached photoelectrochemistry once more, but now Tributsch speaks about what has rapidly become the major area of that topic, photoelectrocatalysis. Close to this chapter, and indeed intellectually connected with it, is that by Schmickler and Schultze about electron transfer reac­ tions at oxide-covered metal electrodes in which theories which are still relatively dubious for metal-solution surfaces are applied to complex systems involving oxides.

1 Perspectives in Electrochemical Physics.- I. Introduction.- II. Importance of Electrochemical Physics.- III. Electrocatalysis by Metals and Alloys.- IV. Electrode Reactions on Semiconductors.- V. Solid-State Properties and Electrochemical Behavior: Corrosion, Anodic Dissolution, and Oxide Growth.- VI. Electrochemical Physics of Metal/ Dielectric Interfaces.- VII. Metal-Plasma ("Gaseous Electrolyte") Interfaces.- VIII. Synopses of Work on Other Themes and Subjects.- References.- 2 Modern State of Double Layer Study of Solid Metals.- I. Introduction.- II. Double Layer Structure at Liquid Metals and Alloys.- III. The Gouy-Chapman-Stern-Grahame (GCSG) Theory for "Uniform" Solid Electrodes.- IV. Capacitance Characteristics of Solid Polycrystalline (PC) Electrodes.- V. Capacitance Characteristics of Individual Single-Crystal Faces.- VI. Crystallographic Inhomogeneity Effects.- VII. Conclusion.- References.- 3 Interfacial Infrared Vibrational Spectroscopy.- I. Introduction.- II. Theoretical Considerations and Experimental Techniques.- III. Applications.- IV. Future Directions.- References.- 4 Photoelectrolysis and Photoelectrochemical Catalysis.- I. Introduction.- II. Photoelectrochemistry of d-Band Sulfides.- III. Tailoring Reactive Surface States for Photoelectrocatalysis.- IV. Experiments Using Semiconductor Electrodes with Paired and Clustered Transition Metals.- V. Discussion.- References.- 5 Electron Transfer Reactions on Oxide-Covered Metal Electrodes.- I. Introduction.- II. Experimental Problems.- III. The Metal-Passive Film-Redox Electrolyte Interface.- IV. Mechanisms of Electron Transfer at Film-Covered Electrodes.- V. Discussion of Some Particular Systems.- VI. Exchange Current Densities and Electronic Properties.- References.- 6 Interfacial Electrostaticsand Electrodynamics in Disperse Systems.- I. Introduction.- II. Interfacial Electrostatics.- III. Interfacial Electrodynamics.- IV. Conclusion and Summary.- References.