Microwave synthesis of Ti/(RuO2)0.5(IrO2)0.5 anodes: Improved electrochemical properties and stability

Abstract

The efficiency of electrochemical technology in treating water contaminated by complex organic pollutants has been widely investigated. Notwithstanding, it is still necessary to develop technologies capable of producing efficient and economically viable electrodes. In this context, the electrochemical oxidation using mixed metal oxide (MMO) anodes is a promisor alternative for wastewater treatment. However, the production of these anodes through thermal decomposition in electric furnaces demands a lot of production time. Here, we report an innovative method based on hybrid microwave irradiation to produce MMO anodes of Ti/(RuO2)0.5(IrO2)0.5 composition. The developed method uses simple apparatus and is faster than other conventional methods, thus decreasing the production costs. The anodes prepared at different calcination temperatures (300, 350, and 400 °C) using microwaves irradiation were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction, cyclic voltammetry, electrochemical impedance spectroscopy, and accelerated service life tests. Besides, the results were compared with those obtained using the conventional heating method. The microwave-produced anodes calcined at 350 °C have the longest service lifetime, which is estimated as 15 years, which is 3.5-fold more than the conventionally made anodes. In addition, this anode has improved electrochemical performance when compared with the conventionally prepared anodes, showing the highest voltammetric charge (1.6-fold). Moreover, this anode removes 100% of color and 64% of TOC after 60 min of electrolysis of the model molecule methylene blue dye. Therefore, the developed method allows for producing materials with improved electrocatalytic properties and enhanced stability at short synthesis times.