“…Ti 4 þ (458.6 eV) represents Ti-O bonds, which exists as a form of TiO 2 . Ti 3 þ (457.1 eV) is related to the O preferential sputtering of TiO 2 by Ar þ , which leads to the anionic deficiencies [22,23]. Peak percentage of Ti2p deconvoluted components are calculated (as shown in Table 3) based on area of deconvolutions.…”