Figure 3
XPS spectra of Mg surface after immersion in HBSSs without and with 2.5 mM NADH: (a) the entire range of the binding energy survey for Mg surfaces after immersion in HBSSs without and with NADH for 1 and 48 h (black: Mg before immersion, red: Mg immersed in HBSS without NADH for 1 h, blue: Mg immersed in HBSS with 2.5 mM NADH for 1 h, and cyan: Mg immersed in HBSS with 2.5 mM NADH for 48 h). (b) Detailed N 1 s spectra for each spectrum in (a). (c) Curve fitting of N 1 s spectra for Mg surface immersed in HBSS with NADH for 1 h. Distinct pyridinic and pyrrolic peaks are clearly observed. (d) Detailed C 1 s spectra for each spectrum in (a). (e) Curve fitting of C 1 s spectra for Mg surface immersed in HBSS with NADH for 1 h. C-O peak appears in spectrum of Mg immersed in HBSS with NADH for 1 h, whereas the peak disappeared after 48 h of reaction. (f) Detailed P 2p spectra for each spectrum in (a). (g,h) Entire (left) and magnified (right) depth profiles of the corrosion product layer formed on the Mg surfaces after immersion in HBSS without (g) and with (h) NADH for 1 h. (i) Depth profile of the corrosion product layer formed on the Mg surfaces after immersion in HBSS with NADH for 48 h.
