Characterization of Ti electrodes electrophoretically coated with IrO2-Ta2O5 films with different Ir:Ta molar ratios

Electrochemical degradation of amoxicillin in acidic aqueous medium using TiO2-based electrodes modified by oxides of transition metals

“…During the electrochemical analysis, different redox processes were obtained, in the case of IrO 2 -Ta 2 O 5 |TiO 2,nt showed the Ir + 2 /Ir + 4 and Ir + 4 /Ir + 5 , in the case of RuO 2 -Ta 2 O 5 |TiO 2,nt showed the Ru + 3 /Ru + 4 and Ru + 4 /Ru + 6 , and in the case of PbO 2 -Ta 2 O 5 |TiO 2,nt showed the Pb + 2 /Pb + 3 and Pb + 3 /Pb + 4 . From polarization curves, 100 µA cm − 2 was selected to be sure that electro-oxidation of AMX took place where the generation of hydroxyl radicals is developed (Herrada et al 2018(Herrada et al , 2020León et al 2020), with the highest oxidation redox state of the Ir (Eq. 6), Ru (Eq.…”

“…The Ru-Ta and Ir-Ta ratios employed in the precursors' solutions were 100:0, 30:70, 50:50, 70:30 and 100:0 v/v in a two electrodes electrochemical cell, where the Ti plate or cylinder was the working electrode with a Ti plate or mesh as counter-electrode, respectively (Fig. 1), which were used in the electrodeposition as it has been reported before (Herrada et al 2018(Herrada et al , 2020León et al 2020). After electrophoretic deposition of Ru-Ta and Ir-Ta with the different ratios, the synthesis of metal oxides was obtained in two-step thermal decomposition, 523 K for 10 min, and 723 K for 1 h (Herrada et al 2018(Herrada et al , 2020León et al 2020).…”

“…With these results, 100 mA cm -2 was selected to be sure that electro-oxidation of AMX took place where the generation of hydroxyl radicals is developed (Herrada et al 2018(Herrada et al , 2020León et al 2020), with the highest oxidation redox state of the Ir (Eq. 6), Ru (Eq.…”

“…Advanced oxidation process (AOPs) with modi ed electrodes are other promise technology, which shows high removal percentages of pharmaceutical compounds as paracetamol (Brillas et al 2005) AOPs are used the dimensional stable anodes (DSA ® ), which are constructed by a thin lm of transition metal oxides over metal as titanium (Ti) by its low cost; the Ti is sandblasted to increase the exposed area to include the metallic oxides, as it has been reported previously (Herrada et al 2016(Herrada et al , 2018(Herrada et al , 2020León et al 2020).…”

“…To modify the TiO 2,nt by electrophoretic anodization with PbO 2 and Ta 2 O 5 in a relation v/v of 100:0, 30:70, 50:50 and 70:30, the precursors solutions used were 0.5 mol L − 1 Pb(NO 3 ) 2 (Meyer, 99 %) in 0.1 mol L − 1 HNO 3 (J. T. Baker, 70 %) and 1.0 mol L − 1 TaCl 5 (Strem Chemicals, 99.9 %) in isopropanol (Karal, 99.5 %)(Herrada et al 2016(Herrada et al , 2018(Herrada et al , 2020Trasatti and Petrii 1991) applying a current density of 50 mA cm − 2 by 5 s (León et al 2020) in a two electrodes electrochemical cell, where the Ti plate or cylinder was the working electrode with a Ti plate or mesh as counter-electrode, respectively (Fig.1).To modify the TiO 2,nt by electrophoretic anodization of Ir, Ru, and Ta a current density of 20 mA cm − 2 by 20 min with constant stirring (300 rpm) was used, the precursors' solutions used were 0.1 mol L − 1 H 2 IrCl Stream Chemicals, 99.9 %) in 50 % HCl (J. T. Baker, 38 %) and isopropanol (Karal, 99.5 %) in a relation 2:1; in the case of Ru deposition, 0.1 mol L − 1 RuCl 3 •H 2 O (Strem Chemicals, 99.9 %) in 50 % HCl and isopropanol 2:1, and 1 mol L − 1 TaCl 5 (Strem Chemicals, 99.9 %) in isopropanol under vigorous stirring.…”