Alachlor removal performance of Ti/Ru0.3Ti0.7O2 anodes prepared from ionic liquid solution

Abstract

Electrochemical processes have a considerable impact on the treatment of contaminated water and wastewater, since water reuse is becoming increasingly necessary. One of the most important variables in electrochemical degradation of organic substances is the electrode material. Several materials have been used successfully as anodes, highlighting those of boron-doped diamond and mixed metal oxide (MMO). The first one is characterized by the high generation of hydroxyl radicals while the second is well known for generating different oxidant species depending on the electrolyte solution composition. The present work aims to develop MMO anodes through thermal decomposition using 1-butylimidazolium hydrogen sulfate, an ionic liquid, as solvent in the precursor solution preparation. The ionic liquid prepared anodes characterization was performed by different techniques such as, scanning electron microscopy (SEM), X-ray diffraction and cyclic voltammetry, and their electrocatalytic performance was evaluated by the electrochemical degradation of alachlor. The commercial electrode presented larger internal area than the electrodes produced by the alternative method, but its efficiency was ca. 16% lower and its energy consumption was 16% higher than the laboratory-made electrode and calcined at 550 °C. Based on SEM results, this behavior can be attributed to the distribution of RuO2 on the surface of the laboratory-made electrodes in comparison to the commercial one. Furthermore, the ionic liquid prepared electrodes showed an increase at least 8% in the voltammetric charge in the stability tests.