Optical second harmonic generation from a catalytically active molybdenum electrode

• Published in: Applied surface science 1998-09, Vol.135 (1-4), p.46-52
• Main Authors: Lovell, M.A., Roy, D.
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Double layer; Electrocatalysis; Exact sciences and technology; Metals. Metallurgy; Molybdenum; Nonlinear susceptibility; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Optical properties of specific thin films, surfaces, and low-dimensional structures; Physics; Second harmonic generation; Surface electron density
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/S0169-4332(98)00307-9

Second harmonic generation (SHG) from an electrochemically controlled Mo surface is detected by using 7 ns laser pulses at a fundamental wavelength of 1064 nm. When this electrode is used as a catalytic support for hydrogen evolution, the optical signal shows a correlation with the reaction current. Considerations of surface kinetics indicate that this observed correlation is a result of free electron-mediated changes in surface conditions. The results of this work reinforce the currently recognized utility of SHG as a probe of reactive metal surfaces. These new data for Mo also contribute to the expansion of the presently known domain of SHG studies of electrochemical systems.