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

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 IrOx electrodes with ultralow iridium loading. The IrOx electrode prepared at 100 mV s(-1) for 100 cycles exhibited a superior mass activity of 3.11 A mgIr(-1), while the IrOx 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 IrOx-TWE/Ti can continuously catalyze OER in 0.5 M H2SO4 at 50 mA cm(-2) for 150 h with a slight performance decay, demonstrating a supper large stability number of 2.78 x 105. This work provides some valuable insights into the application of electrodeposition-based iridium oxide to practical industrial systems.