In this study, the effect of peroxydisulfate ion on electrochemical behavior of natural chalcopyrite in 0.5M H2SO4 was investigated by means of AC/DC electrochemical tests and atomic force microscopy (AFM). Regarding potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS), increase in peroxydisulfate ion concentration accelerates the electrochemical dissolution of the chalcopyrite electrode. Also, Mott-Schottky measurements proved that peroxydisulfate ion decreases n-type semiconducting properties of the chalcopyrite passive layer. Finally, atomic force microscopy showed directly that in presence of peroxydisulfate ion, chalcopyrite more severely corrodes compared with the blank sulfuric solution. (C) 2016 Elsevier Ltd. All rights reserved.