Release Time:2020-03-02  Hits:

Indexed by: Journal Papers

Date of Publication: 2020-02-14

Journal: NANO-MICRO LETTERS

Included Journals: SCIE、EI

Volume: 12

Issue: 1

ISSN: 2311-6706

Key Words: Oxygen evolution reaction; Multiphase hybrid; Two-dimensional nanomaterials; Rare-earth oxides; Ionic layer epitaxy

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 La2O3 nanosheets hybridized with uniform La2O3 nanoparticles (La2O3@NP-NS). Significantly improved OER performance is observed from the nanosheets with a nanometer-scale thickness. The as-synthesized 2.27-nm La2O3@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 ohm. 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 IrO2 and RuO2. This work presents a sustainable approach toward the development of highly efficient electrocatalysts with largely reduced mass loading of precious elements.