Modulating space charge of FeP/CoP p-n heterojunction for boosting oxygen evolution reaction

Shaqi Fu; Cheng Peng; Yuancong Luo; Lingli Cheng; Xuechun Yang; Zheng Jiao

doi:10.1016/j.jcis.2024.03.060

Modulating space charge of FeP/CoP p-n heterojunction for boosting oxygen evolution reaction

J Colloid Interface Sci. 2024 Jun 15:664:349-359. doi: 10.1016/j.jcis.2024.03.060. Epub 2024 Mar 11.

Authors

Shaqi Fu¹, Cheng Peng¹, Yuancong Luo¹, Lingli Cheng², Xuechun Yang³, Zheng Jiao⁴

Affiliations

¹ School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, PR China.
² School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, PR China. Electronic address: chenglingli@t.shu.edu.cn.
³ School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, PR China. Electronic address: xuechunyang@i.shu.edu.cn.
⁴ Shanghai Applied Radiation Institute, Shanghai University, Shanghai 201800, PR China. Electronic address: zjiao@shu.edu.cn.

PMID: 38479271
DOI: 10.1016/j.jcis.2024.03.060

Abstract

Surface reconstruction of electrocatalysts is an effective strategy to modulate the space charge distribution to enhance the electrocatalytic activity. The p-n heterostructured FeP/CoP-2D octagonal nanoplates were successfully constructed by cation-exchange method. The space charge effect caused by the p-n heterojunction accelerated the electron transfer, optimized the electronic structure, and improved the activity of the active sites during the oxygen evolution reaction process. As a result, FeP/CoP-2D required only 247 mV overpotential to achieve a current density of 10 mA cm^-2 with a Tafel slope as low as 68 mV dec^-1. Density-functional theory calculations confirmed that the construction of p-n heterojunctions can enhance the adsorption of *OH in the active centers and optimize the Gibbs free energy of the OER reaction. This study provides an effective and feasible strategy for constructing p-n heterojunctions to modulate the space charge state for optimizing the OER performance of electrocatalysts.

Keywords: Bimetal synergistic effect; OER; Space charge effect; TMP; p-n heterojunction.