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论文类型：期刊论文

发表时间：2020-02-14

发表刊物：NANO-MICRO LETTERS

收录刊物：EI、SCIE

卷号：12

期号：1

ISSN号：2311-6706

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

摘要：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.