A Study on the Triangular-Wave Electrodeposition of Iridium Oxide on Ti

Abstract

Iridium oxide is recognized as the best oxygen evolution anode material due to its excellent electrocatalytic activity and long-term stability in acidic environment. Electrodeposition, as a new method for preparing iridium oxide catalysts, has attracted extensive attention in recent years. We report a triangular-wave electrodeposition method for the preparation of iridium oxide electrodes and successfully synthesized highly active IrO x electrodes with ultralow iridium loading. The IrO x electrode prepared at 100 mV s −1 for 100 cycles exhibited a superior mass activity of 3.11 A mg Ir −1 , while the IrO x electrodeposited at 20 mV s −1 for 500 cycles has the best apparent electrocatalytic activity, Tafel slope as low as 54.75 mV dec −1 . Physical characterization and electrochemical experiments show that the calcination treatment plays an important role in enhancing the OER performance of the electrodes. Remarkably, the calcined IrO x -TWE/Ti can continuously catalyze OER in 0.5 M H 2 SO 4 at 50 mA cm −2 for 150 h with a slight performance decay, demonstrating a supper large stability number of 2.78 × 10 5 . This work provides some valuable insights into the application of electrodeposition-based iridium oxide to practical industrial systems.