TY - JOUR
T1 - Synchrotron-based XPS and NEXAFS study of surface chemical species during electrochemical oxidation of chalcopyrite
AU - Yang, Yi
AU - Harmer-Bassell, Sarah
AU - Chen, Miao
PY - 2015/6/11
Y1 - 2015/6/11
N2 - Abstract The surface chemical information of massive chalcopyrite electrode during electrochemical oxidation was studied by SXPS, NEXAFS and Raman spectroscopy. The electrochemical studies show that there was an activated region for chalcopyrite anodic dissolution between 550 and 630 mV (vs. Ag/AgCl), accompanied by two passive regions nearby. The spectroscopic studies suggest a thin film of non-stoichiometric sulfur-rich layer formed in the first passive region, likely to be responsible for the passivation. In the active region, S22 - species and covellite were also found, which could be the cause of the potential surge. When the potential was increased to 650 mV, another passive region appeared. At the same time, S22 - and covellite started to dissolve, leaving a highly metal deficient polysulfide and elemental sulfur layer on the chalcopyrite surface.
AB - Abstract The surface chemical information of massive chalcopyrite electrode during electrochemical oxidation was studied by SXPS, NEXAFS and Raman spectroscopy. The electrochemical studies show that there was an activated region for chalcopyrite anodic dissolution between 550 and 630 mV (vs. Ag/AgCl), accompanied by two passive regions nearby. The spectroscopic studies suggest a thin film of non-stoichiometric sulfur-rich layer formed in the first passive region, likely to be responsible for the passivation. In the active region, S22 - species and covellite were also found, which could be the cause of the potential surge. When the potential was increased to 650 mV, another passive region appeared. At the same time, S22 - and covellite started to dissolve, leaving a highly metal deficient polysulfide and elemental sulfur layer on the chalcopyrite surface.
KW - Chalcopyrite
KW - Electrochemistry
KW - NEXAFS
KW - Passivation
KW - SXPS
UR - http://www.scopus.com/inward/record.url?scp=84930948048&partnerID=8YFLogxK
U2 - 10.1016/j.hydromet.2015.05.011
DO - 10.1016/j.hydromet.2015.05.011
M3 - Article
SN - 0304-386X
VL - 156
SP - 89
EP - 98
JO - HYDROMETALLURGY
JF - HYDROMETALLURGY
M1 - 4098
ER -