Synthesis and characterization of ternary metallic oxide electrodes containing (SnO₂)₉₃Sb₅M₂ (M = Ce, ta, Bi, Gd) using an ionic liquid as the precursor solvent

Abstract

The present study synthesized mixed metal oxide (MMO) anodes composed of (SnO2)93Sb5M2(M=Ce,Ta,Bi,Gd) through thermal decomposition calcinated at 500, 550, and 600 °C. The anodes were characterized by linear and cyclic voltammetry, electrochemical impedance spectroscopy, service lifetime tests, and morphology factors. Furthermore, physical characterizations included X-ray diffractometry and scanning electron microscopy to obtain information on their crystallographic structure and surface morphology, respectively. Finally, electrocatalytic activity was tested by electrolysis for 1 h in solutions containing 10 ppm of Diuron® using various electrolytes (Na2SO4, Na2CO3, NaNO3, NaCl). The highest superficial area and oxygen evolution onset potential, the longest service lifetime, and considerable Diuron® degradation rates in all electrolytes were obtained for (SnO2)93Sb5Ce2 (32%). However, it is essential to highlight the outstanding service lifetime presented by (SnO2)93Sb5Bi2 (46.32 h), overcoming the results for (SnO2)93Sb5Ce2 by over 50-fold. This behavior is associated with the peculiar nanoflower star-like surface organization seen in the scanning electron microscopy images.