Surface-Electronic-Structure Reconstruction of Perovskite via Double-Cation Gradient Etching for Superior Water Oxidation

Jingyan Zhang; Junfu Li; Chenglin Zhong; Pinxian Xi; Dongliang Chao; Daqiang Gao

doi:10.1021/acs.nanolett.1c02623

Surface-Electronic-Structure Reconstruction of Perovskite via Double-Cation Gradient Etching for Superior Water Oxidation

Nano Lett. 2021 Oct 13;21(19):8166-8174. doi: 10.1021/acs.nanolett.1c02623. Epub 2021 Sep 23.

Authors

Jingyan Zhang¹, Junfu Li¹, Chenglin Zhong^{2

3}, Pinxian Xi⁴, Dongliang Chao³, Daqiang Gao¹

Affiliations

¹ Key Laboratory for Magnetism and Magnetic Materials of MOE, Key Laboratory of Special Function Materials and Structure Design of MOE, Lanzhou University, Lanzhou 730000, China.
² College of Chemistry and Chemical Engineering, Linyi University, Linyi, Shandong 276005, China.
³ Laboratory of Advanced Materials, Fudan University, Shanghai 200433, China.
⁴ Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province and The Research Center of Biomedical Nanotechnology, Lanzhou University, Lanzhou 730000, China.

PMID: 34553939
DOI: 10.1021/acs.nanolett.1c02623

Abstract

Reconstructing the surface-electronic-structure of catalysts for efficient electrocatalytic activity is crucial but still under intense exploration. Herein, we introduce a double-cation gradient etching technique to manipulate the electronic structure of perovskite LaCoO₃. With the gradient dissolution of cations, the surface was reconstructed, and the perovskite/spinel heterostructure V-LCO/Co₃O₄ (V-LCO refers to LaCoO₃ with La and Co vacancies) can be realized. Its surface-electronic-structure is effectively regulated due to the heterogeneous interface effect and abundant vacancies, resulting in a significantly enhanced activity for oxygen evolution reaction (OER). The V-LCO/Co₃O₄ exhibits low electrochemical activation energy and 2 orders of magnitude higher carrier concentrations (1.36 × 10²¹ cm^-3) compared with LCO (6.03 × 10¹⁹ cm^-3). Density functional theory (DFT) calculation unveils that the directional reconstruction of surface-electronic-structure enables the d-band center of V-LCO/Co₃O₄ to a moderate position, endowing perfect adsorption strength for oxo groups and thus promoting the electrocatalytic activity.

Keywords: Perovskite/spinel catalysts; cation deficiencies; d-band center; electronic structure; heterogeneous interfaces.