Adsorption and Diffusion Behavior of Cl^- on Sputtering Fe–20Cr Nanocrystalline Thin Film in Acid Solution（pH = 2）

The adsorption and diffusion behavior of Cl~- on sputtering Fe-20 Cr nanocrystalline（NC） thin film compared with corresponding coarse crystalline（CC） alloy has been studied in HCl ＋ NaCl solution（pH = 2,[Cl~-]=0.1 mol/L） by electrochemical techniques,X-ray photoelectron spectroscopy（XPS） and the firstprinciples calculations.The XPS results show that adsorption and diffusion of Cl~- in the passive film has been inhibited on NC thin film.Ultra-violet photoelectron spectroscopy（UPS） results show that the work function Φ s of NC thin film（4.7 eV） is higher than that of CC alloy（4.5 eV）.The theoretical calculations and valence electron structure analysis were used to understand the effect of nanocrystallization in this work.