Effect of the TiO2 precursor phase on the synthesis of TiO2 Black impregnated electrodes in the degradation of acetaminophen solutions.

Abstract

Black TiO2 impregnated electrodes were synthesized using a modified dip-coating method with 6 layers, to account for the influence of the precursor phase (anatase, rutile, and P25), and their physical properties upon the response on photo electrooxidation of acetaminophen. The thermal treatment under H2+Ar successfully narrowed the band gap and generated a formation of oxygen vacancies and Ti3+ species, confirmed through UV-Vis DRS and photoluminescence (PL) spectroscopy. Treated anatase phase exhibited the greatest band gap reduction, while rutile and P25 showed superior structural stability. The evaluation of acetaminophen degradation revealed a strong dependence on electrolyte medium; the process was ineffective on sulfate medium (Na2SO4, 0.1 M), but highly effective on chloride medium (NaCl, 0.1M). This analysis corroborated that dominant degradation pathway is indirect oxidation through electrogenerated active chlorine species. Rutile and P25 electrodes achieved the highest removal performance, with a minimum C/Co value of 0.631 and 0.650, respectively.