Electrolyte Solutions and Solvent Dependency

When the electrolyte is changed, it will not only change the double-layer structure of the electrochemical interface but also influence the electrochemical reaction rates, and even the potential window. For example, the double layer will be compressed or expanded with the increase or decrease in the concentration of the electrolyte, respectively. Depending on the electrolyte, nonspecific or specific adsorption may occur on the electrode surface. The specifically adsorbed ions, due to a strong interaction with the metal surface, will possibly induce a shift of surface plasmon resonance. The electrolyte ion may also be coadsorbed with the adsorbates in a competitive or induced way for example, thiourea is coadsorbed with CIO4 and/or 804 on the Ag electrode [38]. 

From the above points it may be concluded on the one hand that EC-SERS is among the most complicated SERS systems. Yet, on the other hand, it provides more flexibility for investigating the interfacial structure and mechanism of complex systems by changing the experimental conditions, such as the electrode material, electrolyte, solvent, electrode potential and temperature in the fields of both SERS and electrochemistry. 

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