## 3 Results and Discussion
### Corrosion Protection Evaluation
#### 3.2.3 Electrochemical Studies  
The EIS plots of mild steel panels in the presence or absence of Ce\({}_{\mathrm{x}}\)Ti\({}_{\mathrm{y}}\)O\({}_{\mathrm{z}}\) nanocontainers loaded with ATT after exposure to the corrosive environment are depicted in Figure 9. Considering the EIS Bode curves after 24 h of immersion, it is clearly denoted that the presence of the inhibitor resulted in a \begin{table}
\begin{tabular}{c c c} \hline \hline
**Main Raman Peaks (cm\({}^{-1}\))** & **Assignment** & **Samples** \\ \hline
154 & \
\begin{tabular}{c} symmetric stretch of interlayer \\ chloride ions in green rust \\ hematite \\ 273 \\ 393 \\ 683 \\ 715 \\ 776 \\ 1362 \\ 1613 \\ \end{tabular} &
\begin{tabular}{c} Mild Steel-3.5\%NaCl \\ maghemite \\ maghemite \\ ferrihydrite \\ ferrihydrite \\ ferrihydrite \\ \end{tabular} \\ \hline
185 &
\begin{tabular}{c} symmetric stretch of interlayer \\ chloride ions in green rust \\ \end{tabular} \\
341 & Fe-S due to ATT \\
406 & NCS of the ring due to ATT \\
469 & Fe-S due to ATT \\
788 & N-H out of plane due to ATT \\
1037 & N-N due to ATT \\
1146 & C-N due to ATT \\
1391 & C-N due to ATT \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Classification of the Raman spectra peaks. Figure 8: Raman spectra of mild steel immersed into 3.5 wt.% NaCl for 144 h: (a) Mild Steel-3.5%NaCl, (b) Mild Steel-3.5%NaCl-ATT. higher EIS modulus compared to that of the Mild Steel-3.5%NaCl indicating an increase in the mild steel corrosion protection. The same results were obtained after 144 h of exposure to 3.5 wt.%NaCl indicating improved corrosion protection of mild steel due to the introduction of Ce\({}_{x}\)Ti\({}_{y}\)O\({}_{z}\) nanocontainers loaded with ATT inhibitor and the consequent release of the inhibitor. The EIS Bode plots for both the untreated mild steel after exposure to 3.5 wt.% NaCl (Mild Steel-3.5 NaCl) for either 24 or 144 h can be described with one time constant in the low frequency range that is attributed to the corrosion process. On the other hand, the systems including Ce\({}_{x}\)Ti\({}_{y}\)O\({}_{z}\) nanocontainers loaded with ATT inhibitor (Mild Steel-3.5 NaCl-ATT) after exposure to 3.5 wt.% NaCl for either 24 or 144 h can be characterized with one in the middle frequency range that is ascribed to a film formation between the mild steel surface and the ATT compounds, and a second one in the middle-low frequency range that is assigned to the corrosion process. However, as the immersion time elapsed from 24 to 144 h, the relative time constant moved to lower frequencies because of the increase in the corrosion active area and the corresponding double layer capacitance enhancement. The equivalent circuit for both the untreated mild steels after exposure to 3.5 wt.% NaCl (Mild Steel-3.5 NaCl) for either 24 or 144 included three components and corresponded to an EIS spectrum comprising of one time constant. In particular, it consisted of the solution resistance (\(R_{\text{sol}}\)), the charge transfer resistance together with a double layer CPE (\(R_{\text{ct}}\)-\(\text{CPE}_{\text{dl}}\)) that are attributed to the presence of corrosion active pits at the mild steel surface Figure 10A. Figure 9: EIS plots recorded after exposure to 3.5 wt.% NaCl for: 24 h Mild Steel-3.5 NaCl, (open circle); 24 h Mild Steel-3.5 NaCl-ATT, (filled circle); 144 h Mild Steel-3.5 NaCl, (open square); 144 h Mild Steel-3.5 NaCl-ATT, (filled square). Considering the systems including Ce\({}_{x}\)Ti\({}_{y}\)O\({}_{x}\) nanocontainers loaded with ATT inhibitor (Mild Steel-3.5 NaCl-ATT) after exposure to 3.5 wt.% NaCl for either 24 or 144 h, the relative equivalent circuit consisted of five components and corresponded to an EIS spectra of two relaxation times (Figure 10B).