fig4

Figure 4. Electrochemical degradation of SA by the sea urchin-like La-doped MnO₂ and MnO₂ catalysts. The UV-vis absorption spectra of mixed solution of Na₂SO₄ and SA during electrolysis by (A) pure FTO, (B) La-doped MnO₂ and (C) MnO₂ catalysts at 2.1 V for different times; (D) The comparison of electrochemical degradation efficiency and static degradation efficiency of SA; (E) Degradation efficiency of SA by La-doped MnO₂ and MnO₂ catalysts at different times; (F) The electrocatalytic degradation kinetics of SA. The comparison of the electrochemical degradation efficiency of SA using (G) La-doped MnO₂ and (H) MnO₂ in the presence of TBA, MeOH, or p-BQ; (I) The comparison of the electrocatalytic degradation kinetics of SA with TBA, MeOH, and p-BQ. SAs: Sulfonamides; FTO: fluorine-doped tin oxide; UV-vis: ultraviolet-visible; TBA: tert-butanol; p-BQ: p-Benzoquinone; MeOH: methanol.