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

• Published in: New journal of chemistry 2023-01, Vol.47 (5), p.2619-2625
• Main Authors: Wang, Xuefeng, Jang, Haeseong, Li, Zijian, Li, Haisen, Li, Guangkai, Kim, Min Gyu, Ji, Xuqiang, Qin, Qing, Liu, Xien
• Format: Article
• Language: English
• Subjects: Catalysts; Electrocatalysts; Electronic structure; Energy consumption; Energy conversion; Lanthanum; Nanocomposites; Nanomaterials; Nanosheets; Oxygen evolution reactions; Tuning; Water splitting; X ray absorption
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d2nj05464g

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.