## 3 Results and Discussion
### Electrochemical Behavior of CFTX in the Presence of Different Ions
It can be observed that, on the curve corresponding to supporting electrolyte (NaCl solution) an anodic large peak is highlighted (1.3 V) related to the oxidation of chloride ions via chlorine to oxychlorides such as ClO\({}^{-}\), ClO\({}_{2}\)\({}^{-}\), ClO\({}_{3}\)\({}^{-}\) and ClO\({}_{4}\)\({}^{-}\)[23, 26]. Also, the anodic current density reached a maximum of 35 mA\(\cdot\)cm\({}^{-2}\), higher than that revealed in the case of NaF (15 mA\(\cdot\)cm\({}^{-2}\)). Through the cathodic scan (Figure 1b) three reduction peaks are recorded, at potentials of 0.8 V, 0.1 V and \(-\)0.5 V, being attributed to oxychlorides reduction. In the case of the CFTX/F\({}^{-}\) system (Figure 1a), similar effects on the histogram are described with those previously discussed for the CFTX/Cl\({}^{-}\) (Figure 1b), in the sense that no oxidation/reduction peaks are detectable, and at potentials lower than 1.0 V the anodic and cathodic scans overlap. The major difference consists of the current density increase until 25 mA\(\cdot\)cm\({}^{-2}\), in the presence of Cl\({}^{-}\) (Figure 1b) compared to that recorded in the presence of F\({}^{-}\) of 5 mA\(\cdot\)cm\({}^{-2}\) (Figure 1a). Thus, it can be concluded that CFTX was adsorbed on the electrode surface, inhibiting the oxidation processes, but a certain small proportion of CFTX can decompose and/or can react with Cl\({}^{-}\) ions. The cyclic voltammogram obtained on platinum electrode in sodium bromide supporting electrolyte (Figure 1c) displays an oxidation large peak (like a wave), starting at 0.7 V and continuing up to 1.5 V, being assigned to simultaneous oxidation processes of bromide ions and to the oxygen evolution according to reaction 10 [40, 41, 42]. Also, this oxidation peak is more extensive compared to those recorded in the presence of F\({}^{-}\) and Cl\({}^{-}\) ions (Figure 1a,b), suggesting that more intense chemical processes take place in Br\({}^{-}\) presence (Figure 1c). In the presence of CFTX in sodium bromide solution (Figure 1c), the hysteresis shape is changed, the maximum anodic current density slightly decreases and the anodic and cathodic peaks are imperceptible, indicating that the electrogenerated oxybromides rapidly react with drug molecules forming other compounds. A different platinum electrochemical behavior was observed in NaI solution (Figure 1d), when iodine (I\({}_{2}\)) is generated by oxidation of iodide ions, being accelerated by molecular oxygen formed according to reaction 10 [42]. The cathodic process is intensified through the reduction of active species, being revealed by a peak that extends up to a high current density of 30 mA\(\cdot\)cm\({}^{-2}\). CFTX addition in NaI solution (Figure 1d) leads to a formation of a broad peak on anodic scan, which has a corresponding one slightly nuanced on the cathodic scan, at the same potential, suggesting that multiple processes take place implying CFTX/I\({}^{-}\)/I\({}_{3}\)\({}^{-}\) system, substantially changing the reaction environment composition. Consequently, Cl\({}^{-}\), Br\({}^{-}\) and I\({}^{-}\) ions are electrochemically oxidized leading to the occurrence of various halogenated/oxyhalogenated species which can act as powerful oxidants on organic compounds.