Cui Hao, Jia Shijie, Du Tingting, Liu Jiaqing, Lin Xing, Zhang Xin, Yang Fengchun
Xi'an Key Laboratory of Functional Supramolecular Structure and Materials, College of Chemistry and Material Science, Northwest University, Xi'an 710127, China.
International Research Center for Renewable Energy, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710127, China.
ACS Appl Mater Interfaces. 2024 Dec 25;16(51):70477-70488. doi: 10.1021/acsami.4c13756. Epub 2024 Dec 11.
The oxygen evolution reaction (OER) poses a significant kinetic challenge for various critical energy conversion and storage technologies including electrocatalytic water splitting and metal-air batteries. In this study, a LaCoO/NiFe layered double hydroxide (LDH) catalyst was synthesized through the growth of n-type NiFe LDH on the surface of the p-type LaCoO semiconductor, resulting in a p-n heterostructure for a photogenerated carrier-assisted electrocatalytic OER (PCA-eOER). The alignment of their band structures facilitates the formation of an internal electric field at the heterojunction interface, which promotes the creation of oxygen vacancies and enhances electron transport. Under illumination, the expanded visible-light absorption range and built-in electric field work synergistically to improve the generation and separation of photogenerated carriers. Meanwhile, the accumulation of photogenerated holes on the surface of NiFe LDH results in an enhancement in the concentration of high-valent active metal sites, resulting in a boost in the PCA-eOER efficiency. The LaCoO/NiFe LDH has achieved an overpotential of 260 mV at the current density of 10 mA cm, 50 mV lower than in the absence of illumination. In addition, LaCoO/NiFe LDH was assembled into an alkaline water electrolyzer and zinc-air batteries (ZABs), showing excellent practical application capability. We explored the application of LaCoO in a PCA-eOER, which provides a concept for designing PCA-eOER catalysts and advancing the development of perovskite-based catalysts for clean energy conversion technology.
析氧反应（OER）对包括电催化水分解和金属空气电池在内的各种关键能量转换和存储技术构成了重大的动力学挑战。在本研究中，通过在p型LaCoO半导体表面生长n型NiFe层状双氢氧化物（LDH）合成了LaCoO/NiFe层状双氢氧化物催化剂，形成了用于光生载流子辅助电催化OER（PCA-eOER）的p-n异质结构。它们的能带结构排列有利于在异质结界面形成内建电场，促进氧空位的产生并增强电子传输。在光照下，扩展的可见光吸收范围和内建电场协同作用，改善光生载流子的产生和分离。同时，光生空穴在NiFe LDH表面的积累导致高价活性金属位点浓度增加，从而提高了PCA-eOER效率。LaCoO/NiFe LDH在电流密度为10 mA cm时实现了260 mV的过电位，比无光照时低50 mV。此外，LaCoO/NiFe LDH被组装成碱性水电解槽和锌空气电池（ZAB），显示出优异的实际应用能力。我们探索了LaCoO在PCA-eOER中的应用，为设计PCA-eOER催化剂和推动用于清洁能源转换技术的钙钛矿基催化剂的发展提供了一个概念。
