In situ Raman measurements were carried out on an XploRA PLUS Raman spectrometer equipped with a 50×objective and a 638 nm He-Ne laser. All spectra were recorded by using a commercial three-electrode spectro-electrochemical cell. The as prepared materials, Ag/AgCl, and Pt slice were employed as the working, reference, and counter electrode, respectively. Relevant measurements were conducted in 0.1 M H2SO4 electrolyte.