In-situ EC-AFM Observations upon Decay of Nano-Islands on Au(100) Electrodes in 1-Butyl-3-Methyl-Imidazolium Room Temperature Molten Salts; BMImBF₄ and BMImTFSI

抄録

Au(100) single crystal surfaces were investigated using in-situ electrochemical atomic force microscopy (EC-AFM) in 1-butyl-3-methyl-imidazolium tetrafluoroborate (BMImBF₄) and 1-butyl-3-methyl-imidazolium bis (trifluoromethanesulfonyl) imide (BMImTFSI). The protrusions with four-fold symmetry and interatomic distances of 0.3 nm were observed in the potential range from −0.42 to +0.68 V (vs. Fc/Fc⁺ electrode) in BMImBF₄ and from −0.35 to +1.06 V in BMImTFSI. These observations corresponded to a bare and unreconstructed Au(100)-(1×1) structure. The top layer of the multi-layered island on Au(100) collapsed at a constant decay rate in both BMImBF₄ and BMImTFSI and is consistent with previously reported for EMImBF₄, EMImTFSI, and a sulfuric acid aqueous solution.