Cover Feature: Reduction of 4‐Nitrothiophenol on Ag/Au Bimetallic Alloy Surfaces Studied Using Bipolar Raman Spectroelectrochemistry (ChemElectroChem 10/2020)

The Cover Feature illustrates the use of confocal Raman microscopy in conjunction with bipolar electrochemistry to obtain multidimensional spectroelectrochemical data in situ. The bipolar cathode consists of a continuous composition gradient of electrodeposited Ag/Au modified with a 4‐nitrothiophenol (4‐NTP) self‐assembled monolayer (SAM). The alloy gradient is oriented 90° to the applied electric field, and SERS data collected at a series of points across the surface is used to map the redox state of the SAM as a function of electrode potential and alloy composition. Spectroelectrochemical measurements show that, when the alloy composition is mostly Au, 4‐NTP is directly reduced to 4‐aminothiophenol. In contrast, when the Ag content of the alloy increases, a two‐step mechanism becomes operative due to photochemical processes promoted by the changed optical characteristics of the Ag‐rich alloy. More information can be found in the Article by B. Wang et al.