Rosso et al. revealed the surface electronic heterogeneity of UHV fractured surfaces by using STM microscopy and spectroscopy together with LEED, UPS [55] and [56]. Qiu et al. suggested that the transfer of electrons tend to be much faster during the process of oxidation reactions, resulted from the reduced band energy gap and intensified metallic

characters and the probabilities of occurrence to Fe is much larger than S due to the bond cleavage [57]. Nesbitt et al. reached a set of values of valence band spectra on fractured pyrite surface, in the vacuum by using the synchrotron XPS. Seven peaks were identified from 0.8 eV to 16 eV, two peaks were identified in the doublet-like region, at 16 and 13 eV respectively, resulted from the function of S 3s orbital, and sp3 hybridization of S molecular orbital cannot be demonstrated by any data [58] and [59]. The bond Selleck LDK378 lengths of the S S and Fe S is tended to be shortened due to the higher dangling bond density [57]. It is

presented that the tendency of spin polarization of low coordination sites is quite common compared with spin neutral of the sites and the paramagnetic class is more inclined to react with the sites with low coordination defects. Synchrotron XPS is quite known for the suitability to the study of fractured and oxidized surfaces of chalcopyrite with the characters of greater surface sensitivity and spatial and spectral resolution [60] and [61]. BTK inhibitor Harmer et al. detected 2p3/2 spectra of S on a fresh fractured surface by synchrotron XPS to reached the main symmetric peak (161.33 eV), which is caused by the fully-coordinated bulk S atoms. Another peak at 161.88 eV is analyzed by the surface Sn−2 and a value (160.84 eV) is explained by the presence of surface S2−. The chalcopyrite surfaces 0 0 1, 0 1 2, 1 0 0, 1 0 1, 1 1 0, 1 1 1 and 1 1 2 and surfaces of reconstructions have all been studied [51], [52], [62] and [63]. Klauber proposed that the S2−2 detected on fresh fractured surfaces of chalcopyrite through simultaneous

reconstruction of surfaces(mechanical) and redox process(biochemical), could form a pyrite-like surface layer [64]. de Oliveira and Duarte represented that ferric ions (Fe3+) on the surface are normally reduced to ferrous ions (Fe2+), Cu ions are likely to be oxidized and the S ions is either oxidized or reduced Galeterone based on the specific leaching conditions due to characters of the valence and conduction bands [52]. Von Oertzen et al. represented that there are same amount of metal ions and S ions (atoms) on the surface 0 1 2 and the metal ions and S ions (atoms) are obviously divided in the relative position respectively on the surface 1 1 2 [62] and [63]. The exist of conchoidal surface on chalcopyrite is quite common, that usually caused by poor cleavages in the ore and some cationic and anionic dangling bonds (Mn+,S_2,S2−2,S2−2) are contained on a fractured surface [58]. Liu et al.