Enhancing the electrochemical activity of an IrOx-Ta2O5/Ti anode via radiofrequency-driven rapid plasma annealing

Electrochemical oxidation has attracted much attention in the wastewater treatment field due to its strong oxidation performance and control easiness. In the present study, the electrochemical activity of an IrOx–Ta2O5/Ti anode was enhanced via radiofrequency (RF)-driven rapid plasma annealing (RPA) process; a 2.0 MHz plasma jet was applied to the surface of the precursor-brushed IrOx–Ta2O5/Ti anode, changing the surface morphology and electrochemical characteristics of its coating. The final surface morphology, resulting from the subsequent calcination, exhibited a spongy-like microstructure and much smaller cracks compared with the coatings treated with the conventional thermal decomposition (CTD) process. Moreover, the RPA-treated samples showed lower overpotential (j = 10 mA/cm2) of 261 mV (vs. RHE) and higher voltammetric charges (330.26 mC/cm2). Compared with the CTD-treated one, the electrochemical activity of the RPA-treated samples was greatly improved with a comparable stability after additional calcination at 480 °C. This enhancement in the electrochemical performance indicates that an RF plasma jet, as an RPA tool, has a great potential for improving the catalytic activity of IrOx–Ta2O5/Ti anodes.