Nanoparticle-Decorated Ultrathin La2O3 Nanosheets as an Efficient Electrocatalysis for Oxygen Evolution Reactions
Guangyuan Yan, Yizhan Wang, Ziyi Zhang, Yutao Dong, Jingyu Wang, Corey Carlos, Pu Zhang, Zhiqiang Cao, Yanchao Mao, Xudong Wang
Abstract
Abstract Electrochemical catalysts for oxygen evolution reaction are a critical component for many renewable energy applications. To improve their catalytic kinetics and mass activity are essential for sustainable industrial applications. Here, we report a rare-earth metal-based oxide electrocatalyst comprised of ultrathin amorphous La 2 O 3 nanosheets hybridized with uniform La 2 O 3 nanoparticles (La 2 O 3 @NP-NS). Significantly improved OER performance is observed from the nanosheets with a nanometer-scale thickness. The as-synthesized 2.27-nm La 2 O 3 @NP-NS exhibits excellent catalytic kinetics with an overpotential of 310 mV at 10 mA cm −2 , a small Tafel slope of 43.1 mV dec −1 , and electrochemical impedance of 38 Ω. More importantly, due to the ultrasmall thickness, its mass activity, and turnover frequency reach as high as 6666.7 A g −1 and 5.79 s −1 , respectively, at an overpotential of 310 mV. Such a high mass activity is more than three orders of magnitude higher than benchmark OER electrocatalysts, such as IrO 2 and RuO 2 . This work presents a sustainable approach toward the development of highly efficient electrocatalysts with largely reduced mass loading of precious elements.