Surface-Enhanced Resonance Raman Spectroscopy of Adsorbates on Semiconductor Electrode Surfaces.' 2. I n Situ Studies of Transition Metal (Fe and Ru) Complexes on Ag/GaAs and Ag/SI

Various aspects of surface-enhanced resonance Raman spectroscopy (SERRS) of adsorbates (viz., Ru(bpy);+, Fe(b~y) ,~+, Fe(phen);+) on semiconductor (SC) electrodes with Ag overlayers are examined. In situ SERRS spectra are reported for a nonaqueous electrode system, and SERRS signals are monitored with time as Ag is deposited on SC electrode surfaces both electrochemically and photochemically. Other topics to be covered include the resonance enhancement contribution to SERRS, optimum Ag coverages, and enhancement factors. The photoelectrochemistry of Ag/GaAs electrodes is discussed as well as the implications of the SERRS overlayer technique for photoelectrochemical research.