Boosting the OER activity of amorphous IrOx in acidic medium by tuning its electron structure using lanthanum salt nanosheets

Promoting the activity of Ir-based nanomaterials for oxygen evolution reaction (OER) in acid media without losing their durability is crucial for reducing overpotentials in energy conversion, such as electrochemical water splitting. Here, a nanocomposite composed of a-IrOx and lanthanum salt (LaCO3OH) was constructed to further improve its OER activity by tuning the electronic structure of a-IrOx, because a-IrOx is a well-known critical material as the active layer of Ir-based anodic catalysts. The interaction between Ir and La via O atoms as a bridge in the catalyst IrOx/LaCO3OH, verified by X-ray absorption near edge structure spectroscopy, tunes the electronic structure of a-IrOx and thus obviously enhances its activity for the OER in acid media, compared with commercially available IrO2 as well as most of the reported Ir-based OER electrocatalysts. The overpotential of IrOx/LaCO3OH at a current density of 10 mA cm(-2) is 255 mV with a Tafel slope of 55 mV dec(-1). This work reveals that the strong electronic interaction between Ir- and La-based materials can efficiently improve activity and reduce energy consumption, as well as enlarging the family of acidic OER electrocatalysts.

Automated summary

Researchers constructed a nanocomposite of a-IrOx and lanthanum salt (LaCO3OH) to enhance its oxygen evolution reaction (OER) activity in acid media by tuning the electronic structure. The interaction between Ir and La in the catalyst IrOx/LaCO3OH effectively improved its OER activity and expanded the family of acidic OER electrocatalysts.