Thermal suppression of charge disproportionation accelerates interface electron transfer of water electrolysis

• 成果类型: Article
• 署名作者: Lu, Mengfei; Du, Yu; Yan, Shicheng; Yu, Tao; Zou, Zhigang
• 署名单位: Nanjing University; Collaborative Innovation Center of Advanced Microstructures (CICAM); Nanjing University; Nanjing University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-13526
• DOI: 10.1073/pnas.2316054120
• 发表日期: 2024-01-02
• 关键词: transition; temperature

摘要

The sluggish electron transfer kinetics in electrode polarization driven oxygen evolution reaction (OER) result in big energy barriers of water electrolysis. Accelerating the electron transfer at the electrolyte/catalytic layer/catalyst bulk interfaces is an efficient way to improve electricityto- hydrogenefficiency. Herein, the electron transfer at the Sr3Fe2O7@ SrFeOOH bulk/catalytic layer interface is accelerated by heating to eliminate charge disproportionation from Fe4+ to Fe3+ and Fe5+ in Sr3Fe2O7, a physical effect to thermally stabilize high spin Fe4+ (t2g3eg1), providing available orbitals as electron transfer channels without pairing energy. As a result of thermal- induced changes in electronic states via thermal comproportionation, a sudden increase in OER performances was achieved as heating to completely suppress charge disproportionation, breaking a linear Arrhenius relationship. The strategy of regulating electronic states by thermal field opens a broad avenue to overcome the electron transfer barriers in water splitting. Significance The electronic state modifications of materials, such as doping, generating defects, and forming distortions, are the popular methods to improve the OER performances of catalysts. In this route, the electronic states of materials are mainly determined by the compositions and synthetic conditions. Here, we proposed a route, energy field method, to regulate electronic states of materials under heating. As an example, the electron transfer at Sr3Fe2O7@SrFeOOH interface is effectively accelerated when the thermal induced charge comproportionation is introduced to inhibit the occurrence of Fe3+(t2g3eg2) in Sr3Fe2O7, providing more unoccupied orbitals as interface electron transfer channels via Fe4+(t2g3eg1 in Sr3Fe2O7)- O- Fe4+ (in SrFeOOH). The electronic state modifications via energy field methods open a broad avenue to discover materials useful in water splitting.