Yan Guangyuan, Wu Tong, Xing Shuming, Chen Fei, Zhao Biwei, Gao Wenjing
School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, People's Republic of China.
School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, People's Republic of China.
Nanotechnology. 2022 Mar 25;33(24). doi: 10.1088/1361-6528/ac5b55.
It is still highly desired to develop efficient, resource-abundant and inexpensive electrocatalysts to improve the sluggish kinetics of oxygen evolution reaction (OER) in electrochemical water splitting systems. In this work, the large-area ultrathin (2.52 nm thick) Ce-doped LaOnanofilms were developed via a facile and reliable ionic layer epitaxy method with different Ce content. The ultrathin Ce-doped LaOnanofilm with optimum composition of LaCeOexhibited an excellent OER performance with a very low overpotential of 221 mV at 10 mA cmand a small Tafel slope of 33.7 mV dec. A remarkable high mass activity of 6263.2 A gwas also obtained from ultrathin LaCeOnanofilm at the overpotential of 221 mV. Such a high mass activity was three orders of magnitude higher than state-of-the-art commercial IrOpowders (3.8 A g) and more than 30 times higher than LaOnanofilm (196.7 A g) without Ce doping at the same overpotential. This high mass activity was even significantly higher than other recently reported typical OER catalysts. The substantial OER performance gain by the Ce doping was attributed to the improved conductivity and electrochemical active surface areas of nanofilms as a result of favorable tuning on the charge transfer and electronic structures. This work provides a promising approach to develop high-performance two-dimensional (2D) electrocatalysts by effective heteroatom doping strategy.
开发高效、资源丰富且廉价的电催化剂以改善电化学水分解系统中析氧反应（OER）缓慢的动力学，仍然是人们迫切期望的。在这项工作中，通过一种简便可靠的离子层外延方法，制备了具有不同Ce含量的大面积超薄（2.52 nm厚）Ce掺杂LaO纳米薄膜。具有最佳组成LaCeO的超薄Ce掺杂LaO纳米薄膜表现出优异的OER性能，在10 mA cm时过电位低至221 mV，塔菲尔斜率为33.7 mV dec。在221 mV的过电位下，超薄LaCeO纳米薄膜还获得了高达6263.2 A g的显著高质量活性。如此高的质量活性比最先进的商业IrO粉末（3.8 A g）高三个数量级，比相同过电位下未掺杂Ce的LaO纳米薄膜（196.7 A g）高30多倍。这种高质量活性甚至明显高于最近报道的其他典型OER催化剂。Ce掺杂带来的显著OER性能提升归因于通过对电荷转移和电子结构的有利调节，改善了纳米薄膜的导电性和电化学活性表面积。这项工作为通过有效的杂原子掺杂策略开发高性能二维（2D）电催化剂提供了一种有前景的方法。
